Barrier metal film production apparatus, barrier metal film production method, metal film production method, and metal film production apparatus

0001This application is a Divisional application of co-pending U.S. application Ser. No. 11/638,511, filed Dec. 14, 2006, which is a Divisional application of U.S. application Ser. No. 10/277,733, filed Oct. 23, 2002, which is now abandoned, and for which priority is claimed under 35 U.S.C. §120; and this application claims priority of Japanese Patent Application Nos. 2001-348325, 2002-27738, 2002-44289, and 2002-44296, filed on Nov. 14, 2001, Feb. 5, 2002, Feb. 21, 2002 and Feb. 21, 2002, respectively, under 35 U.S.C. §119. The contents of all of the aforementioned applications are hereby incorporated by reference herein in their entireties.

BACKGROUND OF THE INVENTION

00021. Field of the Invention

0003This invention relates to a production apparatus and a production method for a barrier metal film to be formed on the surface of a substrate for eliminating the diffusion of a metal into the substrate and retaining the adhesion of the metal, when a metal film is formed on the surface of the substrate.

0004The present invention also relates to a metal film production method and a metal film production apparatus which can form a film of a metal, with the diffusion of the metal being eliminated and the adhesion of the metal being retained, by treating the surface of a barrier metal film produced on a substrate.

00052. Description of Related Art

0006Semiconductors with electrical wiring have increasingly used copper as a material for the wiring in order to increase the speed of switching, decrease transmission loss, and achieve a high density. In applying the copper wiring, it has been common practice to perform the vapor phase growth method or plating on a substrate having a depression for wiring on its surface, thereby forming a copper film on the surface including the depression.

0007In forming the copper film on the surface of the substrate, a barrier metal film (for example, a nitride of tantalum, tungsten, titanium or silicon) is prepared beforehand on the surface of the substrate in order to eliminate the diffusion of copper into the substrate, and retain the adhesion of copper. When plating is employed, a copper shielding layer is formed on the barrier metal film by physical or chemical vapor deposition, and used also as an electrode. The barrier metal film has been formed by physical vapor deposition such as sputtering.

0008The depression for wiring, formed on the surface of the substrate, tends to be decreased in size, and a demand is expressed for a further reduction in the thickness of the barrier metal film. However, the barrier metal film has been produced by use of sputtering, and its directionality is not uniform. With a tiny depression on the surface of the substrate, therefore, the film is formed at the entrance of the depression before being formed in the interior of the depression, resulting in insufficient burial of the depression. Also, the substrate has been badly damaged.

0009Additionally, the barrier metal film is prepared for the purposes of preventing the diffusion of copper into the substrate and retaining the adhesion of copper. Hence, a nitride of tantalum, tungsten or titanium is formed as a first layer for prevention of copper diffusion, and an active metal, such as tantalum, tungsten or titanium, is formed as a second layer for retention of adhesion to copper. However, the barrier metal film is so thin that it poses difficulty at the present time in performing both functions, the prevention of copper diffusion into the substrate and the retention of copper adhesion. A demand is growing for the advent of a barrier metal film which accomplishes these two functions.

0010In particular, the wiring depression formed on the surface of the substrate is showing a tendency toward compactness, and further thinning of the barrier metal film is demanded. However, the necessary minimum film thickness has increased, if the barrier metal film is constructed in a two-layer structure by forming a nitride of tantalum, tungsten or titanium as a first layer for prevention of copper diffusion, and forming an active metal, such as tantalum, tungsten or titanium, as a second layer for retention of adhesion to copper.

SUMMARY OF THE INVENTION

0011The present invention has been accomplished in light of the circumstances described above. An object of the invention is to provide a barrier metal film production apparatus and a barrier metal film production method which can form a barrier metal film with excellent burial properties and a very small thickness at a high speed. Another object of the invention is to provide a barrier metal film production apparatus and a barrier metal film production method which can form a barrier metal film with excellent adhesion to a metal formed as a film on the surface of the substrate. Still another object of the invention is to provide a metal film production method and a metal film production apparatus capable of forming a barrier metal film which, although very thin, prevents diffusion of a metal and retains adhesion to the metal.

0012According to the present invention, there is provided a barrier metal film production apparatus, comprising:

0013a chamber accommodating a substrate;

0014a metallic etched member provided in the chamber at a position opposed to the substrate;

0015source gas supply means for supplying a source gas containing a halogen to an interior of the chamber between the substrate and the etched member;

0016plasma generation means which converts an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas;

0017excitation means for exciting a nitrogen-containing gas in a manner isolated from the chamber;

0018formation means for forming a metal nitride upon reaction between nitrogen excited by the excitation means and the precursor; and

0019control means which makes a temperature of the substrate lower than a temperature of the formation means to form the metal nitride as a film on the substrate.

0020Thus, a barrier metal film comprising a film of a metal nitride and suppressing diffusion can be prepared by forming a metal with the use of a plasma. The barrier metal film can be formed uniformly to a small thickness. Consequently, the barrier metal film can be formed highly accurately at a high speed with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate.

0021According to the present invention, there is also provided a barrier metal film production apparatus, comprising:

0022a chamber accommodating a substrate;

0023a metallic etched member provided in the chamber at a position opposed to the substrate;

0024source gas supply means for supplying a source gas containing a halogen to an interior of the chamber between the substrate and the etched member;

0025plasma generation means which converts an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas;

0026excitation means for exciting a nitrogen-containing gas in a manner isolated from the chamber;

0027formation means for forming a metal nitride upon reaction between nitrogen excited by the excitation means and the precursor; and

0028control means which makes a temperature of the substrate lower than a temperature of the formation means to form the metal nitride as a film on the substrate, and after film formation of the metal nitride, stops supply of the nitrogen-containing gas, and makes the temperature of the substrate lower than a temperature of the etched member to form the metal component of the precursor as a film on the metal nitride on the substrate.

0029Thus, a barrier metal film comprising a film of a metal nitride and a metal film and with diffusion suppressed and adhesion improved can be prepared by forming a metal by plasmas. The barrier metal film can be formed uniformly to a small thickness. Consequently, the barrier metal film can be formed highly accurately at a high speed with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate.

0030According to the present invention, there is also provided a barrier metal film production apparatus, comprising:

0031a chamber accommodating a substrate;

0032a metallic etched member provided in the chamber at a position opposed to the substrate;

0033source gas supply means for supplying a source gas containing a halogen to an interior of the chamber between the substrate and the etched member;

0034nitrogen-containing gas supply means for supplying a nitrogen-containing gas to an interior of the chamber between the substrate and the etched member;

0035plasma generation means which converts an atmosphere within the chamber into a plasma to generate a source gas plasma and a nitrogen-containing gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas, and that a metal nitride is formed upon reaction between nitrogen and the precursor; and

0036control means which makes a temperature of the substrate lower than a temperature of the etched member to form the metal nitride as a film on the substrate.

0037Thus, a barrier metal film comprising a film of a metal nitride and a metal film and with diffusion suppressed can be prepared by forming a metal by plasmas. The barrier metal film can be formed uniformly to a small thickness. Also, the supply lines for gases can be simplified, and the number of plasma sources can be decreased, so that the product cost can be reduced. Consequently, the barrier metal film can be formed highly accurately at a high speed and at a low cost with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate.

0038According to the present invention, there is also provided a barrier metal film production apparatus, comprising:

0039a chamber accommodating a substrate;

0040a metallic etched member provided in the chamber at a position opposed to the substrate;

0041source gas supply means for supplying a source gas containing a halogen to an interior of the chamber between the substrate and the etched member;

0042nitrogen-containing gas supply means for supplying a nitrogen-containing gas to an interior of the chamber between the substrate and the etched member;

0043plasma generation means which converts an atmosphere within the chamber into a plasma to generate a source gas plasma and a nitrogen-containing gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas, and that a metal nitride is formed upon reaction between nitrogen and the precursor; and

0044control means which makes a temperature of the substrate lower than a temperature of the etched member to form the metal nitride as a film on the substrate, then stops supply of the nitrogen-containing gas, and makes the temperature of the substrate lower than the temperature of the etched member to form the metal component of the precursor as a film on the metal nitride on the substrate.

0045Thus, a barrier metal film comprising a film of a metal nitride and a metal film and with diffusion suppressed and adhesion improved can be prepared by forming a metal by plasmas. The barrier metal film can be formed uniformly to a small thickness. Also, the supply lines for gases can be simplified, and the number of plasma sources can be decreased, so that the product cost can be reduced. Consequently, the barrier metal film can be formed highly accurately at a high speed and at a low cost with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate.

0046According to the present invention, there is also provided a barrier metal film production method comprising:

0047supplying a source gas containing a halogen to an interior of a chamber between a substrate and a metallic etched member;

0048converting an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas;

0049exciting a nitrogen-containing gas in a manner isolated from the chamber accommodating the substrate;

0050forming a metal nitride upon reaction between excited nitrogen and the precursor; and

0051making a temperature of the substrate lower than a temperature of means for formation of the metal nitride to form the metal nitride as a film on the substrate.

0052Thus, a barrier metal film comprising a film of a metal nitride and suppressing diffusion can be prepared by forming a metal by plasma. The barrier metal film can be formed uniformly to a small thickness. Consequently, the barrier metal film can be formed highly accurately at a high speed with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate.

0053According to the present invention, there is also provided a barrier metal film production method comprising:

0054supplying a source gas containing a halogen to an interior of a chamber between a substrate and a metallic etched member;

0055converting an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas;

0056exciting a nitrogen-containing gas in a manner isolated from the chamber accommodating the substrate;

0057forming a metal nitride upon reaction between excited nitrogen and the precursor;

0058making a temperature of the substrate lower than a temperature of means for formation of the metal nitride to form the metal nitride as a film on the substrate; and

0059after film formation of the metal nitride, stopping supply of the nitrogen-containing gas, and making the temperature of the substrate lower than a temperature of the etched member to form the metal component of the precursor as a film on the metal nitride on the substrate.

0060Thus, a barrier metal film comprising a film of a metal nitride and a metal film and with diffusion suppressed and adhesion improved can be prepared by forming a metal by plasmas. The barrier metal film can be formed uniformly to a small thickness. Consequently, the barrier metal film can be formed highly accurately at a high speed with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate.

0061According to the present invention, there is also provided a barrier metal film production method comprising:

0062supplying a source gas containing a halogen and a nitrogen-containing gas to an interior of a chamber between a substrate and a metallic etched member;

0063converting an atmosphere within the chamber into a plasma to generate a source gas plasma and a nitrogen-containing gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas, and that a metal nitride is formed upon reaction between nitrogen and the precursor; and

0064making a temperature of the substrate lower than a temperature of the etched member to form the metal nitride as a film on the substrate.

0065Thus, a barrier metal film comprising a film of a metal nitride and with diffusion suppressed can be prepared by forming a metal by plasmas. The barrier metal film can be formed uniformly to a small thickness. Also, the supply line for gases can be simplified, and the number of plasma sources can be decreased, so that the product cost can be reduced. Consequently, the barrier metal film can be formed highly accurately at a high speed and at a low cost with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate.

0066According to the present invention, there is also provided a barrier metal film production method comprising:

0067supplying a source gas containing a halogen and a nitrogen-containing gas to an interior of a chamber between a substrate and a metallic etched member;

0068converting an atmosphere within the chamber into a plasma to generate a source gas plasma and a nitrogen-containing gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas, and that a metal nitride is formed upon reaction between nitrogen and the precursor;

0069making a temperature of the substrate lower than a temperature of the etched member to form the metal nitride as a film on the substrate; and

0070after film formation of the metal nitride, stopping supply of the nitrogen-containing gas, and making the temperature of the substrate lower than the temperature of the etched member to form the metal component of the precursor as a film on the metal nitride on the substrate.

0071Thus, a barrier metal film comprising a film of a metal nitride and a metal film and with diffusion suppressed and adhesion improved can be prepared by forming a metal by plasmas. The barrier metal film can be formed uniformly to a small thickness. Also, the supply line for gases can be simplified, and the number of plasma sources can be decreased, so that the product cost can be reduced. Consequently, the barrier metal film can be formed highly accurately at a high speed and at a low cost with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate.

0072According to the present invention, there is also provided a barrier metal film production apparatus, comprising:

0073a chamber accommodating a substrate;

0074a metallic etched member provided in the chamber at a position opposed to the substrate;

0075source gas supply means for supplying a source gas containing a halogen into the chamber;

0076nitrogen-containing gas supply means for supplying a gas containing nitrogen into the chamber;

0077plasma generation means which converts an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas, and which converts the atmosphere within the chamber into a plasma to generate a nitrogen-containing gas plasma so that a metal nitride is formed upon reaction between nitrogen and the precursor;

0078control means which makes a temperature of the substrate lower than a temperature of the plasma generation means to form the metal nitride as a barrier metal film on a surface of the substrate;

0079diluent gas supply means for supplying a diluent gas to a site above the surface of the substrate; and

0080surface treatment plasma generation means for performing a surface treatment which converts the atmosphere within the chamber into a plasma to generate a diluent gas plasma so that nitrogen atoms in a superficial layer of the barrier metal film are removed by the diluent gas plasma to decrease a nitrogen content of the superficial layer relative to an interior of a matrix of the barrier metal film.

0081Thus, a barrier metal film comprising a metal nitride layer and a metal layer can be prepared without the increase of the film thickness. Consequently, a barrier metal film production apparatus can be achieved which is capable of forming a barrier metal film at a high speed with excellent burial properties in a very small thickness, and also forming a barrier metal film with excellent adhesion to a metal formed as a film on the surface of the barrier metal film.

0082The barrier metal film production apparatus may further comprise oxygen gas supply means for supplying an oxygen gas into the chamber immediately before formation of the most superficial layer of the barrier metal film is completed; and oxygen plasma generation means which converts the atmosphere within the chamber into a plasma to generate an oxygen gas plasma so that an oxide layer is formed on the most superficial layer of the barrier metal film.

0083Thus, because of an oxide layer, if a metal is deposited on the surface of the barrier metal film, wettability by the metal can be rendered satisfactory, thus increasing adhesion.

0084According to the present invention, there is also provided a barrier metal film production apparatus, comprising:

0085a chamber accommodating a substrate;

0086a metallic etched member provided in the chamber at a position opposed to the substrate;

0087source gas supply means for supplying a source gas containing a halogen into the chamber;

0088nitrogen-containing gas supply means for supplying a gas containing nitrogen into the chamber;

0089plasma generation means which converts an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas, and which converts the atmosphere within the chamber into a plasma to generate a nitrogen-containing gas plasma so that a metal nitride is formed upon reaction between nitrogen and the precursor;

0090control means which makes a temperature of the substrate lower than a temperature of the plasma generation means to form the metal nitride as a barrier metal film on a surface of the substrate;

0091oxygen gas supply means for supplying an oxygen gas to a site above the surface of the substrate; and

0092oxygen plasma generation means for performing a surface treatment which converts the atmosphere within the chamber into a plasma to generate an oxygen gas plasma so that nitrogen atoms in a superficial layer of the barrier metal film are removed by the oxygen gas plasma to decrease a nitrogen content of the superficial layer relative to an interior of a matrix of the barrier metal film, and at the same time, forming an oxide layer on the most superficial layer of the barrier metal film.

0093Thus, a barrier metal film comprising a metal nitride layer and a metal layer can be prepared with a minimum nozzle construction without the increase of the film thickness, and an oxide layer gives satisfactory wettability by a metal deposited on the surface of the barrier metal film. Consequently, a barrier metal film production apparatus can be achieved which is capable of forming a barrier metal film at a high speed with excellent burial properties in a very small thickness, and also forming a barrier metal film with excellent adhesion to a metal formed as a film on the surface of the barrier metal film.

0094According to the present invention, there is also provided a barrier metal film production apparatus, comprising:

0095a chamber accommodating a substrate;

0096a metallic etched member provided in the chamber at a position opposed to the substrate;

0097source gas supply means for supplying a source gas containing a halogen into the chamber;

0098nitrogen-containing gas supply means for supplying a gas containing nitrogen into the chamber;

0099plasma generation means which converts an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas, and which converts the atmosphere within the chamber into a plasma to generate a nitrogen-containing gas plasma so that a metal nitride is formed upon reaction between nitrogen and the precursor;

0100control means which makes a temperature of the substrate lower than a temperature of the plasma generation means to form the metal nitride as a film, for use as a barrier metal film, on a surface of the substrate;

0101oxygen gas supply means for supplying an oxygen gas into the chamber immediately before formation of the most superficial layer of the barrier metal film is completed; and

0102oxygen plasma generation means which converts the atmosphere within the chamber into a plasma to generate an oxygen gas plasma so that an oxide layer is formed on the most superficial layer of the barrier metal film.

0103Thus, a barrier metal film comprising a metal nitride layer can be prepared without the increase of the film thickness, and an oxide layer gives satisfactory wettability by a metal deposited on the surface of the barrier metal film. Consequently, a barrier metal film production apparatus can be achieved which is capable of forming a barrier metal film at a high speed with excellent burial properties in a very small thickness, and also forming a barrier metal film with excellent adhesion to a metal formed as a film on the surface of the barrier metal film.

0104According to the present invention, there is also provided a barrier metal film production apparatus, comprising:

0105a chamber accommodating a substrate;

0106a metallic etched member provided in the chamber at a position opposed to the substrate;

0107source gas supply means for supplying a source gas containing a halogen into the chamber;

0108nitrogen-containing gas supply means for supplying a gas containing nitrogen into the chamber;

0109plasma generation means which converts an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas, and which converts the atmosphere within the chamber into a plasma to generate a nitrogen-containing gas plasma so that a metal nitride is formed upon reaction between nitrogen and the precursor;

0110control means which makes a temperature of the substrate lower than a temperature of the plasma generation means to form the metal nitride as a film on a surface of the substrate, then makes the temperature of the substrate lower than the temperature of the plasma generation means and stops supply of the gas containing nitrogen from the nitrogen-containing gas supply means, thereby forming the metal component of the precursor as a film on the metal nitride for use as a barrier metal film;

0111oxygen gas supply means for supplying an oxygen gas into the chamber immediately before formation of the most superficial layer of the barrier metal film is completed; and

0112oxygen plasma generation means which converts the atmosphere within the chamber into a plasma to generate an oxygen gas plasma so that an oxide layer is formed on the most superficial layer of the barrier metal film.

0113Thus, a barrier metal film comprising a metal nitride layer and a metal layer can be prepared without the increase of the film thickness, and an oxide layer gives satisfactory wettability by a metal deposited on the surface of the barrier metal film. Consequently, a barrier metal film production apparatus can be achieved which is capable of forming a barrier metal film at a high speed with excellent burial properties, and also forming a barrier metal film with excellent adhesion to a metal formed as a film on the surface of the barrier metal film.

0114According to the present invention, there is also provided a barrier metal film production apparatus, comprising:

0115a chamber accommodating a substrate;

0116a metallic etched member provided in the chamber at a position opposed to the substrate;

0117source gas supply means for supplying a source gas containing a halogen into the chamber;

0118plasma generation means which converts an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas;

0119excitation means for exciting a gas containing nitrogen in a manner isolated from the chamber;

0120formation means for forming a metal nitride upon reaction between nitrogen excited by the excitation means and the precursor;

0121control means which makes a temperature of the substrate lower than a temperature of the formation means to form the metal nitride as a film on the substrate for use as a barrier metal film;

0122oxygen gas supply means for supplying an oxygen gas into the chamber immediately before formation of the most superficial layer of the barrier metal film is completed; and

0123oxygen plasma generation means which converts, the atmosphere within the chamber into a plasma to generate an oxygen gas plasma so that an oxide layer is formed on the most superficial layer of the barrier metal film.

0124Thus, a barrier metal film comprising a metal nitride layer can be prepared without the increase of the film thickness, an oxide layer gives satisfactory wettability by a metal deposited on the surface of the barrier metal film, and the substrate can be free from exposure to a nitrogen-containing gas plasma. Consequently, a barrier metal film production apparatus can be achieved which is capable of forming a barrier metal film at a high speed with excellent burial properties in a very small thickness without exerting the influence of the nitrogen-containing gas plasma upon the substrate, and also forming a barrier metal film with excellent adhesion to a metal formed as a film on the surface of the barrier metal film.

0125According to the present invention, there is also provided a barrier metal film production apparatus, comprising:

0126a chamber accommodating a substrate;

0127a metallic etched member provided in the chamber at a position opposed to the substrate;

0128source gas supply means for supplying a source gas containing a halogen into the chamber;

0129plasma generation means which converts an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas;

0130excitation means for exciting a gas containing nitrogen in a manner isolated from the chamber;

0131formation means for forming a metal nitride upon reaction between nitrogen excited by the excitation means and the precursor;

0132control means which makes a temperature of the substrate lower than a temperature of the formation means to form the metal nitride as a film on the substrate, and after film formation of the metal nitride, stops supply of the nitrogen-containing gas and makes the temperature of the substrate lower than a temperature of the etched member, thereby forming the metal component of the precursor as a film on the metal nitride on the substrate for use as a barrier metal film;

0133oxygen gas supply means for supplying an oxygen gas into the chamber immediately before formation of the most superficial layer of the barrier metal film is completed; and

0134oxygen plasma generation means which converts the atmosphere within the chamber into a plasma to generate an oxygen gas plasma so that an oxide layer is formed on the most superficial layer of the barrier metal film.

0135Thus, a barrier metal film comprising a metal nitride layer can be prepared without the increase of the film thickness, an oxide layer gives satisfactory wettability by a metal deposited on the surface of the barrier metal film, and the substrate can be free from exposure to a nitrogen-containing gas plasma. Consequently, a barrier metal film production apparatus can be achieved which is capable of forming a barrier metal film at a high speed with excellent burial properties without exerting the influence of the nitrogen-containing gas plasma upon the substrate, and also forming a barrier metal film with excellent adhesion to a metal formed as a film on the surface of the barrier metal film.

0136The barrier metal film production apparatus may further comprise hydrogen gas supply means for supplying a hydrogen gas into the chamber; and hydroxyl group plasma generation means which converts the atmosphere within the chamber into a plasma to generate a hydrogen gas plasma so that hydroxyl groups are formed on the oxide layer.

0137Thus, hydroxyl groups are formed, so that hydrophilicity can be increased, and adhesion of a metal deposited on the surface can be further increased.

0138According to the present invention, there is also provided a barrier metal film production method comprising:

0139supplying a source gas containing a halogen and a nitrogen-containing gas to an interior of a chamber between a substrate and a metallic etched member;

0140converting an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas, and also converting the atmosphere within the chamber into a plasma to generate a nitrogen-containing gas plasma so that a metal nitride is formed upon reaction between nitrogen and the precursor;

0141making a temperature of the substrate lower than a temperature of plasma generation means to form the metal nitride as a barrier metal film on a surface of the substrate;

0142supplying a diluent gas to a site within the chamber above the surface of the substrate; and

0143performing a surface treatment which converts the atmosphere within the chamber into a plasma to generate a diluent gas plasma so that nitrogen atoms in a superficial layer of the barrier metal film are removed by the diluent gas plasma to decrease a nitrogen content of the superficial layer relative to an interior of a matrix of the barrier metal film.

0144Thus, a barrier metal film comprising a metal nitride layer and a metal layer can be prepared without the increase of the film thickness. Consequently, a barrier metal film production method can be achieved which is capable of forming a barrier metal film at a high speed with excellent burial properties in a very small thickness, and also forming a barrier metal film with excellent adhesion to a metal formed as a film on the surface of the barrier metal film.

0145The barrier metal film production method may further comprise supplying an oxygen gas into the chamber immediately before formation of the most superficial layer of the barrier metal film is completed; and converting the atmosphere within the chamber into a plasma to generate an oxygen gas plasma so that an oxide layer is formed on the most superficial layer of the barrier metal film.

0146Thus, the oxide layer gives satisfactory wettability by a metal deposited on the surface of the barrier metal film, thereby increasing adhesion to the metal.

0147According to the present invention, there is also provided a barrier metal film production method comprising:

0148supplying a source gas containing a halogen and a nitrogen-containing gas to an interior of a chamber between a substrate and a metallic etched member;

0149converting an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas, and also converting the atmosphere within the chamber into a plasma to generate a nitrogen-containing gas plasma so that a metal nitride is formed upon reaction between nitrogen and the precursor;

0150making a temperature of the substrate lower than a temperature of plasma generation means to form the metal nitride as a barrier metal film on a surface of the substrate;

0151supplying an oxygen gas to a site above the surface of the substrate; and

0152performing a surface treatment which converts the atmosphere within the chamber into a plasma to generate an oxygen gas plasma so that nitrogen atoms in a superficial layer of the barrier metal film are removed by the oxygen gas plasma to decrease a nitrogen content of the superficial layer relative to an interior of a matrix of the barrier metal film, while forming an oxide layer on the most superficial layer of the barrier metal film.

0153Thus, a barrier metal film comprising a metal nitride layer and a metal layer can be prepared with a minimum nozzle construction without the increase of the film thickness, and an oxide layer gives satisfactory wettability by a metal deposited on the surface of the barrier metal film. Consequently, a barrier metal film production method can be achieved which is capable of forming a barrier metal film at a high speed with excellent burial properties in a very small thickness, and also forming a barrier metal film with excellent adhesion to a metal formed as a film on the surface of the barrier metal film.

0154According to the present invention, there is also provided a barrier metal film production method comprising:

0155supplying a source gas containing a halogen and a nitrogen-containing gas to an interior of a chamber between a substrate and a metallic etched member;

0156converting an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas, and also converting the atmosphere within the chamber into a plasma to generate a nitrogen-containing gas plasma so that a metal nitride is formed upon reaction between nitrogen and the precursor;

0157making a temperature of the substrate lower than a temperature of plasma generation means to form the metal nitride as a film on a surface of the substrate for use as a barrier metal film;

0158supplying an oxygen gas into the chamber immediately before formation of the most superficial layer of the barrier metal film is completed; and

0159converting the atmosphere within the chamber into a plasma to generate an oxygen gas plasma so that an oxide layer is formed on the most superficial layer of the barrier metal film.

0160Thus, a barrier metal film comprising a metal nitride layer can be prepared without the increase of the film thickness, and an oxide layer gives satisfactory wettability by a metal deposited on the surface of the barrier metal film. Consequently, a barrier metal film production method can be achieved which is capable of forming a barrier metal film at a high speed with excellent burial properties in a very small thickness, and also forming a barrier metal film with excellent adhesion to a metal formed as a film on the surface of the barrier metal film.

0161According to the present invention, there is also provided a barrier metal film production method comprising:

0162supplying a source gas containing a halogen and a nitrogen-containing gas to an interior of a chamber between a substrate and a metallic etched member;

0163converting an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas, and also converting the atmosphere within the chamber into a plasma to generate a nitrogen-containing gas plasma so that a metal nitride is formed upon reaction between nitrogen and the precursor;

0164making a temperature of the substrate lower than a temperature of plasma generation means to form the metal nitride as a film on a surface of the substrate, then making the temperature of the substrate lower than the temperature of the plasma generation means and stopping supply of the gas containing nitrogen, thereby forming the metal component of the precursor as a film on the metal nitride for use as a barrier metal film;

0165supplying an oxygen gas into the chamber immediately before formation of the most superficial layer of the barrier metal film is completed; and

0166converting the atmosphere within the chamber into a plasma to generate an oxygen gas plasma so that an oxide layer is formed on the most superficial layer of the barrier metal film.

0167Thus, a barrier metal film comprising a metal nitride layer and a metal layer can be prepared without the increase of the film thickness, and an oxide layer gives satisfactory wettability by a metal deposited on the surface of the barrier metal film. Consequently, a barrier metal film production method can be achieved which is capable of forming a barrier metal film at a high speed with excellent burial properties, and also forming a barrier metal film with excellent adhesion to a metal formed as a film on the surface of the barrier metal film.

0168According to the present invention, there is also provided a barrier metal film production method comprising:

0169supplying a source gas containing a halogen and a nitrogen-containing gas to an interior of a chamber between a substrate and a metallic etched member;

0170converting an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas, and also exciting the gas containing nitrogen in a manner isolated from the chamber accommodating the substrate;

0171forming a metal nitride upon reaction between excited nitrogen and the precursor;

0172making a temperature of the substrate lower than a temperature of means for formation of the metal nitride to form the metal nitride as a film on the substrate for use as a barrier metal film;

0173supplying an oxygen gas at a site above a surface of the substrate immediately before formation of the most superficial layer of the barrier metal film is completed; and

0174converting the atmosphere within the chamber into a plasma to generate an oxygen gas plasma so that an oxide layer is formed on the most superficial layer of the barrier metal film.

0175Thus, a barrier metal film comprising a metal nitride layer can be prepared without the increase of the film thickness, an oxide layer gives satisfactory wettability by a metal deposited on the surface of the barrier metal film, and the substrate can be free from exposure to a nitrogen-containing gas plasma. Consequently, a barrier metal film production method can be achieved which is capable of forming a barrier metal film at a high speed with excellent burial properties in a very small thickness without exerting the influence of the nitrogen-containing gas plasma upon the substrate, and also forming a barrier metal film with excellent adhesion to a metal formed as a film on the surface of the barrier metal film.

0176According to the present invention, there is also provided a barrier metal film production method comprising:

0177supplying a source gas containing a halogen and a nitrogen-containing gas to an interior of a chamber between a substrate and a metallic etched member;

0178converting an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas, and also exciting the gas containing nitrogen in a manner isolated from the chamber accommodating the substrate;

0179forming a metal nitride upon reaction between excited nitrogen and the precursor;

0180making a temperature of the substrate lower than a temperature of means for formation of the metal nitride to form the metal nitride as a film on the substrate, and after film formation of the metal nitride, stopping supply of the nitrogen-containing gas and making the temperature of the substrate lower than a temperature of the etched member, thereby forming the metal component of the precursor as a film on the metal nitride on the substrate for use as a barrier metal film;

0181supplying an oxygen gas at a site above a surface of the substrate immediately before formation of the most superficial layer of the barrier metal film is completed; and

0182converting the atmosphere within the chamber into a plasma to generate an oxygen gas plasma so that an oxide layer is formed on the most superficial layer of the barrier metal film.

0183Thus, a barrier metal film comprising a metal nitride layer can be prepared without the increase of the film thickness, an oxide layer gives satisfactory wettability by a metal deposited on the surface of the barrier metal film, and the substrate can be free from exposure to a nitrogen-containing gas plasma. Consequently, a barrier metal film production method can be achieved which is capable of forming a barrier metal film at a high speed with excellent burial properties without exerting the influence of the nitrogen-containing gas plasma upon the substrate, and also forming a barrier metal film with excellent adhesion to a metal formed as a film on the surface of the barrier metal film.

0184The barrier metal film production method may further comprise supplying a hydrogen gas into the chamber; and converting the atmosphere within the chamber into a plasma to generate a hydrogen gas plasma so that hydroxyl groups are formed on the oxide layer.

0185Thus, hydrophilicity can be increased, so that adhesion of a metal deposited on the surface can be further increased.

0186According to the present invention, there is also provided a barrier metal film production method involving treatment of a surface of a substrate having a barrier metal film of a metal nitride formed thereon, comprising:

0187performing a surface treatment which removes nitrogen atoms in a superficial layer of the barrier metal film to decrease a nitrogen content of the superficial layer relative to an interior of a matrix of the barrier metal film, thereby substantially forming a metal layer on the superficial layer.

0188Thus, the substantial metal layer and the metal nitride layer can be formed with a single-layer thickness, and a barrier metal film with a very small thickness can be produced, with diffusion of metal being prevented and adhesion to the metal being retained. Consequently, a metal wiring process can be stabilized.

0189According to the present invention, there is also provided a metal film comprising a metal layer substantially formed on a superficial layer of a barrier metal film of a metal nitride formed on a surface of a substrate, said metal layer being formed by performing a surface treatment which removes nitrogen atoms in the superficial layer of the barrier metal film to decrease a nitrogen content of the superficial layer relative to an interior of a matrix of the barrier metal film.

0190Thus, there is obtained a metal film which has a barrier metal film comprising the substantial metal layer and the metal nitride layer formed with a single-layer thickness, and produced with a very small thickness, with diffusion of metal being prevented and adhesion to the metal being retained, and which can stabilize a metal wiring process.

0191According to the present invention, there is also provided a barrier metal film production method involving treatment of a surface of a substrate having a barrier metal film of a metal nitride formed thereon, comprising:

0192performing a surface treatment which etches the barrier metal film on the surface of the substrate with a diluent gas plasma to flatten the barrier metal film.

0193Thus, a barrier metal film can be produced, with diffusion of metal being prevented and adhesion to the metal being retained. Consequently, a metal wiring process can be stabilized.

0194According to the present invention, there is also provided a barrier metal film production method involving treatment of a surface of a substrate having a barrier metal film of a metal nitride formed thereon, comprising:

0195performing a surface treatment which etches the barrier metal film on the surface of the substrate with a diluent gas plasma to flatten the barrier metal film, and removes nitrogen atoms in a superficial layer of the barrier metal film by the diluent gas plasma to decrease a nitrogen content of the superficial layer relative to an interior of a matrix of the barrier metal film.

0196Thus, the substantial metal layer and the metal nitride layer can be formed with a single-layer thickness, and a barrier metal film with a very small thickness can be produced, with diffusion of metal being prevented and adhesion to the metal being retained. Consequently, a metal wiring process can be stabilized.

0197According to the present invention, there is also provided a metal film production method comprising:

0198supplying a source gas containing a halogen to an interior of a chamber between a substrate and a metallic etched member;

0199converting an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas, and also exciting a gas containing nitrogen in a manner isolated from the chamber accommodating the substrate;

0200forming a metal nitride upon reaction between excited nitrogen and the precursor;

0201making a temperature of the substrate lower than a temperature of means for formation of the metal nitride to form the metal nitride as a film on the substrate for use as a barrier metal film; and

0202performing a surface treatment which etches the barrier metal film on a surface of the substrate with a diluent gas plasma to flatten the barrier metal film.

0203Thus, a barrier metal film can be produced such that the barrier metal film is prepared, and then subjected to a treatment for preventing diffusion of metal and retaining adhesion to the metal. Consequently, a metal wiring process can be stabilized.

0204According to the present invention, there is also provided a metal film production method comprising:

0205supplying a source gas containing a halogen to an interior of a chamber between a substrate and a metallic etched member;

0206converting an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas, and also exciting a gas containing nitrogen in a manner isolated from the chamber accommodating the substrate;

0207forming a metal nitride upon reaction between excited nitrogen and the precursor;

0208making a temperature of the substrate lower than a temperature of means for formation of the metal nitride to form the metal nitride as a film on the substrate for use as a barrier metal film; and

0209performing a surface treatment which etches the barrier metal film on a surface of the substrate with a diluent gas plasma to flatten the barrier metal film, and removes nitrogen atoms in a superficial layer of the barrier metal film by the diluent gas plasma to decrease a nitrogen content of the superficial layer relative to an interior of a matrix of the barrier metal film.

0210Thus, after a barrier metal film is prepared, the substantial metal layer and the metal nitride layer can be formed with a single-layer thickness. Hence, a barrier metal film having a very small thickness can be produced, with diffusion of metal being prevented and adhesion to the metal being retained. Consequently, a metal wiring process can be stabilized.

0211According to the present invention, there is also provided a metal film production method comprising:

0212performing a surface treatment which generates a diluent gas plasma within a chamber accommodating a substrate having a barrier metal film of a metal nitride formed thereon, to etch the barrier metal film on a surface of the substrate with the diluent gas plasma, thereby flattening the barrier metal film;

0213then supplying a source gas containing a halogen into the chamber;

0214converting an atmosphere within the chamber into a plasma to generate a source gas plasma so that an etched member made of a metal is etched with the source gas plasma to form a precursor within the chamber from a metal component contained in the etched member and the source gas; and

0215making a temperature of the substrate lower than a temperature of the etched member to form the metal component of the precursor as a film on the substrate having the barrier metal film flattened.

0216Thus, a metal can be formed as a film through the production of a barrier metal film subjected to a treatment for preventing diffusion of metal and retaining adhesion to the metal. Consequently, a metal wiring process can be stabilized.

0217According to the present invention, there is also provided a metal film production method comprising:

0218performing a surface treatment which generates a diluent gas plasma within a chamber accommodating a substrate having a barrier metal film of a metal nitride formed thereon, to etch the barrier metal film on a surface of the substrate with the diluent gas plasma, thereby flattening the barrier metal film, and removes nitrogen atoms in a superficial layer of the barrier metal film by the diluent gas plasma to decrease a nitrogen content of the superficial layer relative to an interior of a matrix of the barrier metal film;

0219then supplying a source gas containing a halogen into the chamber;

0220converting an atmosphere within the chamber into a plasma to generate a source gas plasma so that an etched member made of a metal is etched with the source gas plasma to form a precursor within the chamber from a metal component contained in the etched member and the source gas; and

0221making a temperature of the substrate lower than a temperature of the etched member to form the metal component of the precursor as a film on the substrate having the barrier metal film flattened and having the nitrogen content of the superficial layer relatively decreased.

0222Thus, the substantial metal layer and the metal nitride layer can be formed with a single-layer thickness. Hence, a metal can be formed as a film through the production of a barrier metal film having a very small thickness while preventing diffusion of metal and retaining adhesion to the metal. Consequently, a metal wiring process can be stabilized.

0223The metal film production method may further comprise applying a densification treatment for densifying metal atoms in a superficial layer of the barrier metal film after flattening the barrier metal film and also relatively decreasing the nitrogen content of the superficial layer.

0224Thus, diffusion of the component of the metal film can be prevented reliably.

0225In the metal film production method, the diluent gas plasma may be an argon gas plasma. Thus, the treatment can be performed reliably with the use of an inexpensive gas.

0226According to the present invention, there is also provided a metal film production apparatus, comprising:

0227a chamber accommodating a substrate;

0228a metallic etched member provided in the chamber at a position opposed to the substrate;

0229halogen gas supply means for supplying a source gas containing a halogen to an interior of the chamber between the substrate and the etched member;

0230barrier plasma generation means which converts an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas;

0231excitation means for exciting a gas containing nitrogen in a manner isolated from the chamber;

0232formation means for forming a metal nitride upon reaction between nitrogen excited by the excitation means and the precursor;

0233control means which makes a temperature of the substrate lower than a temperature of the formation means to form the metal nitride as a film on the substrate for use as a barrier metal film;

0234diluent gas supply means for supplying a diluent gas to a site above a surface of the substrate; and

0235surface treatment plasma generation means which converts the atmosphere within the chamber into a plasma to generate a diluent gas plasma so that the barrier metal film on the surface of the substrate is etched with the diluent gas plasma to flatten the barrier metal film.

0236Thus, there can be produced a barrier metal film subjected to treatment for preventing diffusion of metal and retaining adhesion to the metal. Consequently, a metal wiring process can be stabilized.

0237According to the present invention, there is also provided a metal film production apparatus, comprising:

0238a chamber accommodating a substrate;

0239a metallic etched member provided in the chamber at a position opposed to the substrate;

0240halogen gas supply means for supplying a source gas containing a halogen to an interior of the chamber between the substrate and the etched member;

0241barrier plasma generation means which converts an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas;

0242excitation means for exciting a gas containing nitrogen in a manner isolated from the chamber;

0243formation means for forming a metal nitride upon reaction between nitrogen excited by the excitation means and the precursor;

0244control means which makes a temperature of the substrate lower than a temperature of the formation means to form the metal nitride as a film on the substrate for use as a barrier metal film;

0245diluent gas supply means for supplying a diluent gas to a site above a surface of the substrate; and

0246surface treatment plasma generation means for performing a surface treatment which converts the atmosphere within the chamber into a plasma to generate a diluent gas plasma so that the barrier metal film on the surface of the substrate is etched with the diluent gas plasma to flatten the barrier metal film, and removes nitrogen atoms in a superficial layer of the barrier metal film to decrease a nitrogen content of the superficial layer relative to an interior of a matrix of the barrier metal film.

0247Thus, the substantial metal layer and the metal nitride layer can be formed with a single-layer thickness. Hence, a barrier metal film having a very small thickness can be produced, with diffusion of metal being prevented and adhesion to the metal being retained. Consequently, a metal wiring process can be stabilized.

0248According to the present invention, there is also provided a metal film production apparatus, comprising:

0249a chamber accommodating a substrate having a barrier metal film of a metal nitride formed thereon;

0250diluent gas supply means for supplying a diluent gas to an interior of the chamber above a surface of the substrate;

0251surface treatment plasma generation means which converts an atmosphere within the chamber into a plasma to generate a diluent gas plasma so that the barrier metal film on the surface of the substrate is etched with the diluent gas plasma to flatten the barrier metal film;

0252a metallic etched member provided in the chamber;

0253source gas supply means for supplying a source gas containing a halogen to an interior of the chamber between the substrate and the etched member;

0254plasma generation means which converts the source gas containing the halogen into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas; and

0255control means which makes a temperature of the substrate lower than a temperature of the etched member to form the metal component of the precursor as a film on the flattened barrier metal film.

0256Thus, a metal film can be formed through the production of a barrier metal film subjected to a treatment for preventing diffusion of metal and retaining adhesion to the metal. Consequently, a metal wiring process can be stabilized.

0257According to the present invention, there is also provided a metal film production apparatus, comprising:

0258a chamber accommodating a substrate having a barrier metal film of a metal nitride formed thereon;

0259diluent gas supply means for supplying a diluent gas to an interior of the chamber above a surface of the substrate;

0260surface treatment plasma generation means which converts an atmosphere within the chamber into a plasma to generate a diluent gas plasma so that the barrier metal film on the surface of the substrate is etched with the diluent gas plasma to flatten the barrier metal film, and also removes nitrogen atoms in a superficial layer of the barrier metal film by the diluent gas plasma to decrease a nitrogen content of the superficial layer relative to an interior of a matrix of the barrier metal film;

0261a metallic etched member provided in the chamber;

0262source gas supply means for supplying a source gas containing a halogen to an interior of the chamber between the substrate and the etched member;

0263plasma generation means which converts the source gas containing the halogen into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas; and

0264control means which makes a temperature of the substrate lower than a temperature of the etched member to form the metal component of the precursor as a film on the barrier metal film flattened and having the nitrogen content of the superficial layer relatively decreased.

0265Thus, the substantial metal layer and the metal nitride layer can be formed with a single-layer thickness. Hence, a metal film can be formed through the production of a barrier metal film having a very small thickness while preventing diffusion of metal and retaining adhesion to the metal. Consequently, a metal wiring process can be stabilized.

0266The metal film production apparatus may further comprise densification treatment means for densifying metal atoms in the superficial layer after flattening the barrier metal film and also relatively decreasing the nitrogen content of the superficial layer. Thus, diffusion of the component of the metal film can be prevented reliably.

0267In the metal film production apparatus, the diluent gas plasma may be an argon gas plasma. Thus, the treatment can be performed reliably with the use of an inexpensive gas.

0268According to the present invention, there is also provided a metal film formed by flattening a barrier metal film of a metal nitride on a surface of a substrate by etching with a diluent gas plasma.

0269Thus, the resulting metal film has a barrier metal film retaining adhesion, and can stabilize a metal wiring process.

0270According to the present invention, there is also provided a metal film formed by a surface treatment which flattens a barrier metal film of a metal nitride on a surface of a substrate by etching with a diluent gas plasma, and removes nitrogen atoms in a superficial layer of the barrier metal film by the diluent gas plasma to decrease a nitrogen content of the superficial layer relative to an interior of a matrix of the barrier metal film.

0271Thus, there is obtained a metal film which has a barrier metal film comprising the substantial metal layer and the metal nitride layer formed with a single-layer thickness, and produced with a very small thickness, with diffusion of metal being prevented and adhesion to the metal being retained, and which can stabilize a metal wiring process.

0272According to the present invention, there is also provided a metal film production method involving treatment of a surface of a substrate having a barrier metal film of a metal nitride formed thereon, comprising:

0273performing a surface treatment which reacts the barrier metal film on the surface of the substrate in a reducing gas atmosphere to remove nitrogen atoms in a superficial layer of the barrier metal film, thereby decreasing a nitrogen content of the superficial layer relative to an interior of a matrix of the barrier metal film.

0274Thus, a barrier metal film with a very small thickness and comprising the substantial metal layer and the metal nitride layer formed with a single-layer thickness can be produced, with diffusion of metal being prevented and adhesion to the metal being retained. Consequently, a metal wiring process can be stabilized.

0275According to the present invention, there is also provided a metal film production method comprising:

0276supplying a source gas containing a halogen to an interior of a chamber between a substrate and a metallic etched member;

0277converting an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas, and also exciting a gas containing nitrogen in a manner isolated from the chamber accommodating the substrate;

0278forming a metal nitride upon reaction between excited nitrogen and the precursor;

0279making a temperature of the substrate lower than a temperature of means for formation of the metal nitride to form the metal nitride as a film on the substrate for use as a barrier metal film; and

0280performing a surface treatment which reacts the barrier metal film on a surface of the substrate in a reducing gas atmosphere to remove nitrogen atoms in a superficial layer of the barrier metal film, thereby decreasing a nitrogen content of the superficial layer relative to an interior of a matrix of the barrier metal film.

0281Thus, a barrier metal film with a very small thickness and comprising the substantial metal layer and the metal nitride layer formed with a single-layer thickness can be produced, with diffusion of metal being prevented and adhesion to the metal being retained. Consequently, a metal wiring process can be stabilized.

0282According to the present invention, there is also provided a metal film production method comprising:

0283performing a surface treatment in a chamber accommodating a substrate having a barrier metal film of a metal nitride formed thereon, said surface treatment comprising reacting the barrier metal film on a surface of the substrate in a reducing gas atmosphere to remove nitrogen atoms in a superficial layer of the barrier metal film, thereby decreasing a nitrogen content of the superficial layer relative to an interior of a matrix of the barrier metal film;

0284then supplying a source gas containing a halogen into the chamber;

0285converting an atmosphere within the chamber into a plasma to generate a source gas plasma so that a metallic etched member is etched with the source gas plasma to form a precursor within the chamber from a metal component contained in the etched member and the source gas; and

0286making a temperature of the substrate lower than a temperature of the etched member to form the metal component of the precursor as a film on the substrate having the barrier metal film flattened thereon.

0287Thus, a metal film can be formed through the production of a barrier metal film having a very small thickness and comprising the substantial metal layer and the metal nitride layer formed with a single-layer thickness, while preventing diffusion of metal and retaining adhesion to the metal. Consequently, a metal wiring process can be stabilized.

0288According to the present invention, there is also provided a metal film production apparatus, comprising:

0289a chamber accommodating a substrate;

0290a metallic etched member provided in the chamber at a position opposed to the substrate;

0291halogen gas supply means for supplying a source gas containing a halogen to an interior of the chamber between the substrate and the etched member;

0292barrier plasma generation means which converts an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas;

0293excitation means for exciting a gas containing nitrogen in a manner isolated from the chamber;

0294formation means for forming a metal nitride upon reaction between nitrogen excited by the excitation means and the precursor;

0295control means which makes a temperature of the substrate lower than a temperature of the formation means to form the metal nitride as a film on the substrate for use as a barrier metal film;

0296reducing gas supply means for supplying a reducing gas to a site above a surface of the substrate; and

0297surface treatment means which reacts the barrier metal film on the surface of the substrate in a reducing gas atmosphere to remove nitrogen atoms in a superficial layer of the barrier metal film, thereby decreasing a nitrogen content of the superficial layer relative to an interior of a matrix of the barrier metal film.

0298Thus, a barrier metal film with a very small thickness and comprising the substantial metal layer and the metal nitride layer formed with a single-layer thickness can be produced, with diffusion of metal being prevented and adhesion to the metal being retained. Consequently, a metal wiring process can be stabilized.

0299According to the present invention, there is also provided a metal film production apparatus, comprising:

0300a chamber accommodating a substrate having a barrier metal film of a metal nitride formed thereon;

0301reducing gas supply means for supplying a reducing gas to a site above a surface of the substrate;

0302surface treatment means which reacts the barrier metal film on the surface of the substrate in a reducing gas atmosphere to remove nitrogen atoms in a superficial layer of the barrier metal film, thereby decreasing a nitrogen content of the superficial layer relative to an interior of a matrix of the barrier metal film;

0303a metallic etched member provided in the chamber;

0304source gas supply means for supplying a source gas containing a halogen to an interior of the chamber between the substrate and the etched member;

0305plasma generation means which converts the source gas containing the halogen into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas; and

0306control means which makes a temperature of the substrate lower than a temperature of the etched member to form the metal component of the precursor as a film on the barrier metal film having the nitrogen content of the superficial layer relatively decreased.

0307Thus, a metal film can be formed through the production of a barrier metal film having a very small thickness and comprising the substantial metal layer and the metal nitride layer formed with a single-layer thickness, while preventing diffusion of metal and retaining adhesion to the metal. Consequently, a metal wiring process can be stabilized.

0308According to the present invention, there is also provided a metal film formed by a surface treatment which reacts a barrier metal film of a metal nitride on a surface of a substrate in a reducing gas atmosphere to remove nitrogen atoms in a superficial layer of the barrier metal film, thereby decreasing a nitrogen content of the superficial layer relative to an interior of a matrix of the barrier metal film.

0309Thus, there is obtained a metal film which has a barrier metal film comprising the substantial metal layer and the metal nitride layer formed with a single-layer thickness, and produced with a very small thickness, with diffusion of metal being prevented and adhesion to the metal being retained, and which can stabilize a metal wiring process.

0310According to the present invention, there is also provided a metal film production method involving treatment of a surface of a substrate having a barrier metal film of a metal nitride formed thereon, comprising:

0311performing a surface treatment which forms nuclei of silicon atoms on a surface of the barrier metal film on the surface of the substrate by a gas plasma containing silicon.

0312Thus, a barrier metal film with a very small thickness can be produced, with adhesion to metal being retained. Consequently, a metal wiring process can be stabilized.

0313According to the present invention, there is also provided a metal film production method comprising:

0314supplying a source gas containing a halogen to an interior of a chamber between a substrate and a metallic etched member;

0315converting an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas, and also exciting a gas containing nitrogen in a manner isolated from the chamber accommodating the substrate;

0316forming a metal nitride upon reaction between excited nitrogen and the precursor;

0317making a temperature of the substrate lower than a temperature of means for formation of the metal nitride to form the metal nitride as a film on the substrate for use as a barrier metal film; and

0318performing a surface treatment which forms nuclei of silicon atoms on a surface of the barrier metal film on a surface of the substrate by a gas plasma containing silicon.

0319Thus, a barrier metal film with a very small thickness can be produced, with adhesion to metal being retained. Consequently, a metal wiring process can be stabilized.

0320According to the present invention, there is also provided a metal film production method comprising:

0321performing a surface treatment in a chamber accommodating a substrate having a barrier metal film of a metal nitride formed thereon, said surface treatment comprising forming nuclei of silicon atoms on a surface of the barrier metal film on a surface of the substrate by a gas plasma containing silicon;

0322then supplying a source gas containing a halogen into the chamber;

0323converting an atmosphere within the chamber into a plasma to generate a source gas plasma so that a metallic etched member is etched with the source gas plasma to form a precursor within the chamber from a metal component contained in the etched member and the source gas; and

0324making a temperature of the substrate lower than a temperature of the etched member to form the metal component of the precursor as a film on the substrate having the nuclei of silicon atoms formed on the surface of the barrier metal film.

0325Thus, a metal film can be formed through the production of a barrier metal film having a very small thickness and retaining adhesion to metal. Consequently, a metal wiring process can be stabilized.

0326According to the present invention, there is also provided a metal film production apparatus, comprising:

0327a chamber accommodating a substrate;

0328a metallic etched member provided in the chamber at a position opposed to the substrate;

0329halogen gas supply means for supplying a source gas containing a halogen to an interior of the chamber between the substrate and the etched member;

0330barrier plasma generation means which converts an atmosphere within the chamber into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas;

0331excitation means for exciting a gas containing nitrogen in a manner isolated from the chamber;

0332formation means for forming a metal nitride upon reaction between nitrogen excited by the excitation means and the precursor;

0333control means which makes a temperature of the substrate lower than a temperature of the formation means to form the metal nitride as a film on the substrate for use as a barrier metal film;

0334silicon-containing gas supply means for supplying a gas containing silicon to a site above a surface of the substrate; and

0335surface treatment plasma generation means which generates a gas plasma containing silicon to form nuclei of silicon atoms on a surface of the barrier metal film on the surface of the substrate.

0336Thus, a barrier metal film with a very small thickness can be produced, with adhesion to metal being retained. Consequently, a metal wiring process can be stabilized.

0337According to the present invention, there is also provided a metal film production apparatus, comprising:

0338a chamber accommodating a substrate having a barrier metal film of a metal nitride formed thereon;

0339silicon-containing gas supply means for supplying a gas containing silicon to a site above a surface of the substrate;

0340surface treatment plasma generation means which generates a as plasma containing silicon to form nuclei of silicon atoms on a surface of the barrier metal film on the surface of the substrate;

0341a metallic etched member provided in the chamber;

0342source gas supply means for supplying a source gas containing a halogen to an interior of the chamber between the substrate and the etched member;

0343plasma generation means which converts the source gas containing the halogen into a plasma to generate a source gas plasma so that the etched member is etched with the source gas plasma to form a precursor from a metal component contained in the etched member and the source gas; and

0344control means which makes a temperature of the substrate lower than a temperature of the etched member to form the metal component of the precursor as a film on the barrier metal film having the nuclei of silicon atoms formed on the surface thereof.

0345Thus, a metal film can be formed through the production of a barrier metal film having a very small thickness and retaining adhesion to metal. Consequently, a metal wiring process can be stabilized.

0346According to the present invention, there is also provided a metal film formed by applying a surface treatment to a barrier metal film of a metal nitride on a surface of a substrate such that nuclei of silicon atoms are formed on a surface of the barrier metal film on the surface of the substrate by a gas plasma containing silicon.

0347Thus, there is obtained a metal film which has a barrier metal film having a very small thickness and retaining adhesion to metal, and which can stabilize a metal wiring process.

BRIEF DESCRIPTION OF THE DRAWINGS

0348The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:

0349<figref idref="DRAWINGS">FIG. 1</figref> is a schematic side view of a barrier metal film production apparatus according to a first embodiment of the present invention;

0350<figref idref="DRAWINGS">FIG. 2</figref> is a detail view of a substrate on which a barrier metal film has been produced;

0351<figref idref="DRAWINGS">FIG. 3</figref> is a schematic side view of a barrier metal film production apparatus according to a second embodiment of the present invention;

0352<figref idref="DRAWINGS">FIG. 4</figref> is a view taken along the arrowed line IV-IV of <figref idref="DRAWINGS">FIG. 3</figref>;

0353<figref idref="DRAWINGS">FIG. 5</figref> is a view taken along the arrowed line V-V of <figref idref="DRAWINGS">FIG. 4</figref>;

0354<figref idref="DRAWINGS">FIG. 6</figref> is a schematic side view of a barrier metal film production apparatus according to a third embodiment of the present invention;

0355<figref idref="DRAWINGS">FIG. 7</figref> is a schematic side view of a barrier metal film production apparatus according to a fourth embodiment of the present invention;

0356<figref idref="DRAWINGS">FIG. 8</figref> is a schematic side view of a barrier metal film production apparatus according to a fifth embodiment of the present invention;

0357<figref idref="DRAWINGS">FIG. 9</figref> is a schematic side view of a barrier metal film production apparatus according to a sixth embodiment of the present invention;

0358<figref idref="DRAWINGS">FIG. 10</figref> is a schematic side view of a barrier metal film production apparatus according to a seventh embodiment of the present invention;

0359<figref idref="DRAWINGS">FIG. 11</figref> is a schematic side view of a barrier metal film production apparatus according to an eighth embodiment of the present invention;

0360<figref idref="DRAWINGS">FIG. 12</figref> is a schematic side view of a barrier metal film production apparatus according to a ninth embodiment of the present invention;

0361<figref idref="DRAWINGS">FIG. 13</figref> is a sectional view of a substrate illustrating a barrier metal film;

0362<figref idref="DRAWINGS">FIG. 14</figref> is a concept view of a barrier metal film in a treatment for denitrification;

0363<figref idref="DRAWINGS">FIG. 15</figref> is a concept view of the barrier metal film in the treatment for denitrification;

0364<figref idref="DRAWINGS">FIG. 16</figref> is a concept view of a barrier metal film in a treatment for oxide layer formation;

0365<figref idref="DRAWINGS">FIG. 17</figref> is a graph representing the relationship between the contact angle of copper particles and the oxygen concentration of the substrate;

0366<figref idref="DRAWINGS">FIG. 18</figref> is a concept view of a barrier metal film in a treatment for hydroxyl group formation;

0367<figref idref="DRAWINGS">FIG. 19</figref> is a schematic construction drawing showing another example of diluent gas supply means;

0368<figref idref="DRAWINGS">FIG. 20</figref> is a schematic construction drawing of a barrier metal film production apparatus according to a tenth embodiment of the present invention;

0369<figref idref="DRAWINGS">FIG. 21</figref> is a concept view of an example of production of a barrier metal film by the barrier metal film production apparatus according to the tenth embodiment of the present invention;

0370<figref idref="DRAWINGS">FIG. 22</figref> is a schematic side view of a barrier metal film production apparatus according to an eleventh embodiment of the present invention;

0371<figref idref="DRAWINGS">FIG. 23</figref> is a schematic side view of a barrier metal film production apparatus according to a twelfth embodiment of the present invention;

0372<figref idref="DRAWINGS">FIG. 24</figref> is a view taken along the arrowed line XIII-XIII of <figref idref="DRAWINGS">FIG. 23</figref>;

0373<figref idref="DRAWINGS">FIG. 25</figref> is a view taken along the arrowed line XIV-XIV of <figref idref="DRAWINGS">FIG. 24</figref>;

0374<figref idref="DRAWINGS">FIG. 26</figref> is a schematic side view of a barrier metal film production apparatus according to a thirteenth embodiment of the present invention;

0375<figref idref="DRAWINGS">FIG. 27</figref> is a schematic side view of a barrier metal film production apparatus according to a fourteenth embodiment of the present invention;

0376<figref idref="DRAWINGS">FIG. 28</figref> is an outline drawing of an apparatus for a film formation process;

0377<figref idref="DRAWINGS">FIG. 29</figref> is a schematic side view of a metal film production apparatus according to a fifteenth embodiment of the present invention;

0378<figref idref="DRAWINGS">FIG. 30</figref> is a schematic construction drawing showing another example of diluent gas supply means;

0379<figref idref="DRAWINGS">FIG. 31</figref> is a sectional view of a substrate illustrating a barrier metal film;

0380<figref idref="DRAWINGS">FIG. 32</figref> is a concept view of a barrier metal film in a treatment for denitrification;

0381<figref idref="DRAWINGS">FIG. 33</figref> is a concept view of the barrier metal film in the treatment for denitrification;

0382<figref idref="DRAWINGS">FIG. 34</figref> is a schematic side view of a metal film production apparatus according to a sixteenth embodiment of the present invention;

0383<figref idref="DRAWINGS">FIG. 35</figref> is a view taken along the arrowed line VIII-VIII of <figref idref="DRAWINGS">FIG. 34</figref>;

0384<figref idref="DRAWINGS">FIG. 36</figref> is a view taken along the arrowed line IX-IX of <figref idref="DRAWINGS">FIG. 35</figref>;

0385<figref idref="DRAWINGS">FIG. 37</figref> is a schematic side view of a metal film production apparatus according to a seventeenth embodiment of the present invention;

0386<figref idref="DRAWINGS">FIG. 38</figref> is a schematic side view of a metal film production apparatus according to an eighteenth embodiment of the present invention;

0387<figref idref="DRAWINGS">FIG. 39</figref> is a schematic side view of a metal film production apparatus according to a nineteenth embodiment of the present invention;

0388<figref idref="DRAWINGS">FIG. 40</figref> is a conceptual construction drawing of a metal film production apparatus according to a twentieth embodiment of the present invention;

0389<figref idref="DRAWINGS">FIG. 41</figref> is a concept view of a barrier metal film in a treatment for denitrification;

0390<figref idref="DRAWINGS">FIG. 42</figref> is a schematic construction drawing of a metal film production apparatus according to a twenty-first embodiment of the present invention; and

0391<figref idref="DRAWINGS">FIG. 43</figref> is a concept view of a barrier metal film in formation of nuclei of Si.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

0392The first embodiment of the barrier metal film production apparatus and barrier metal film production method of the present invention will be described with reference to <figref idref="DRAWINGS">FIGS. 1 and 2</figref>. <figref idref="DRAWINGS">FIG. 1</figref> is a schematic side view of the barrier metal film production apparatus according to the first embodiment of the present invention. <figref idref="DRAWINGS">FIG. 2</figref> shows details of a substrate on which a barrier metal film has been prepared.

0393As shown in the drawings, a support platform <b>2</b> is provided near the bottom of a cylindrical chamber <b>1</b> made of, say, a ceramic (an insulating material), and a substrate <b>3</b> is placed on the support platform <b>2</b>. Temperature control means <b>6</b> equipped with a heater <b>4</b> and refrigerant flow-through means <b>5</b> is provided in the support platform <b>2</b> so that the support platform <b>2</b> is controlled to a predetermined temperature (for example, a temperature at which the substrate <b>3</b> is maintained at 100 to 200° C.) by the temperature control means <b>6</b>.

0394An upper surface of the chamber <b>1</b> is an opening, which is closed with a metal member <b>7</b>, as an etched member, made of a metal (e.g., W, Ti, Ta, or TiSi). The interior of the chamber <b>1</b> closed with the metal member <b>7</b> is maintained at a predetermined pressure by a vacuum device <b>8</b>. A plasma antenna <b>9</b>, as a coiled winding antenna <b>9</b> of plasma generation means, is provided around a cylindrical portion of the chamber <b>1</b>. A matching instrument <b>10</b> and a power source <b>11</b> are connected to the plasma antenna <b>9</b> to supply power.

0395Nozzles <b>12</b> for supplying a source gas (a Cl₂gas diluted with He or Ar to a chlorine concentration of ≦50%, preferably about 10%), containing chlorine as a halogen, to the interior of the chamber <b>1</b> are connected to the cylindrical portion of the chamber <b>1</b> below the metal member <b>7</b>. The nozzle <b>12</b> is open toward the horizontal, and is fed with the source gas via a flow controller <b>13</b>. Fluorine (F), bromine (Br) or iodine (I) can also be applied as the halogen to be incorporated into the source gas.

0396Slit-shaped opening portions <b>14</b> are formed at a plurality of locations (for example, four locations) in the periphery of a lower part of the cylindrical portion of the chamber <b>1</b>, and one end of a tubular passage <b>15</b> is fixed to each of the opening portions <b>14</b>. A tubular excitation chamber <b>16</b> made of an insulator is provided halfway through the passage <b>15</b>, and a coiled plasma antenna <b>17</b> is provided around the excitation chamber <b>16</b>. The plasma antenna <b>17</b> is connected to a matching instrument <b>18</b> and a power source <b>19</b> to receive power. The plasma antenna <b>17</b>, the matching instrument <b>18</b> and the power source <b>19</b> constitute excitation means. A flow controller <b>20</b> is connected to the other end of the passage <b>15</b>, and an ammonia gas (NH₃gas) as a nitrogen-containing gas is supplied into the passage <b>15</b> via the flow controller <b>20</b>.

0397With the above-described barrier metal film production apparatus, the source gas is supplied through the nozzles <b>12</b> to the interior of the chamber <b>1</b>, and electromagnetic waves are shot from the plasma antenna <b>9</b> into the chamber <b>1</b>. As a result, the Cl₂gas is ionized to generate a Cl₂gas plasma (source gas plasma) <b>21</b>. The Cl₂gas plasma <b>21</b> causes an etching reaction to the metal member <b>7</b>, forming a precursor (M_xCl_y: M is a metal such as W, Ti, Ta or TiSi) <b>22</b>.

0398Separately, the NH₃gas is supplied into the passage <b>15</b> via the flow controller <b>20</b> and fed into the excitation chamber <b>16</b>. By shooting electromagnetic waves from the plasma antenna <b>17</b> into the excitation chamber <b>16</b>, the NH₃gas is ionized to generate an NH₃gas plasma <b>23</b>. Since a predetermined differential pressure has been established between the pressure inside the chamber <b>1</b> and the pressure inside the excitation chamber <b>16</b> by the vacuum device <b>8</b>, the excited ammonia of the NH₃gas plasma <b>23</b> in the excitation chamber <b>16</b> is fed to the precursor (M_xCl_y) <b>22</b> inside the chamber <b>1</b> through the opening portion <b>14</b>.

0399That is, excitation means for exciting the nitrogen-containing gas in the excitation chamber <b>16</b> isolated from the chamber <b>1</b> is constructed. Because of this construction, the metal component of the precursor (M_xCl_y) <b>22</b> and ammonia react to form a metal nitride (MN) (i.e., formation means). At this time, the metal member <b>7</b> and the excitation chamber <b>16</b> are maintained by the plasmas at predetermined temperatures (e.g., 200 to 400° C.) which are higher than the temperature of the substrate <b>3</b>.

0400The metal nitride (MN) formed within the chamber <b>1</b> is transported toward the substrate <b>3</b> controlled to a low temperature, whereby a thin MN film <b>24</b> is formed on the surface of the substrate <b>3</b>. After the thin MN film <b>24</b> is formed, the supply of the NH₃gas and the supply of power to the power source <b>19</b> are cut off. Thus, the precursor (M_xCl_y) <b>22</b> is transported toward the substrate <b>3</b> controlled to a lower temperature than the temperature of the metal member <b>7</b>. The precursor (M_xCl_y) <b>22</b> transported toward the substrate <b>3</b> is converted into only metal (M) ions by a reduction reaction, and directed at the substrate <b>3</b> to form a thin M film <b>25</b> on the thin MN film <b>24</b> on the substrate <b>3</b>. A barrier metal film <b>26</b> is composed of the thin MN film <b>24</b> and the thin M film <b>25</b> (see <figref idref="DRAWINGS">FIG. 2</figref>).

0401The reaction for formation of the thin MN film <b>24</b> can be expressed by: <br />2MCl+2NH₃→2MN↓+HCl↑+2H₂↑

0402The reaction for formation of the thin M film <b>25</b> can be expressed by: <br />2MCl→2M↓+Cl₂↑

0403The gases and the etching products that have not been involved in the reactions are exhausted through an exhaust port <b>27</b>.

0404The source gas has been described, with the Cl₂gas diluted with, say, He or Ar taken as an example. However, the Cl₂gas can be used alone, or an HCl gas can also be applied. If the HCl gas is applied, an HCl gas plasma is generated as the source gas plasma. Thus, the source gas may be any gas containing chlorine, and a gas mixture of an HCl gas and a Cl₂gas is also usable. As the material for the metal member <b>7</b>, it is possible to use an industrially applicable metal such as Ag, Au, Pt or Si.

0405The substrate <b>3</b>, on which the barrier metal film <b>26</b> has been formed, is subjected to a film forming device, which forms a thin copper (Cu) film or a thin aluminum (Al) film on the barrier metal film <b>26</b>. Because of the presence of the barrier metal film <b>26</b>, there arise advantages, for example, such that the thin MN film <b>24</b> eliminates diffusion of Cu into the substrate <b>3</b>, and the thin M film <b>25</b> ensures adhesion of Cu.

0406If the material to be formed as a film is a material unproblematic in terms of adhesion (e.g., Al), or if it is a metal to which the nitride can retain adhesion, the thin M film <b>25</b> can be omitted from the barrier metal film <b>26</b>. Furthermore, the reduction reaction is caused by the temperature difference. However, a reducing gas plasma can be generated separately to produce a reduction reaction.

0407With the above-described barrier metal film production apparatus, the metal is formed by plasmas to produce the barrier metal film <b>26</b>. Thus, the barrier metal film <b>26</b> can be formed uniformly to a small thickness. Consequently, the barrier metal film <b>26</b> can be formed highly accurately at a high speed with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate <b>3</b>.

0408A barrier metal film production apparatus and a barrier metal film production method according to the second embodiment of the present invention will be described with reference to <figref idref="DRAWINGS">FIGS. 3 to 5</figref>. <figref idref="DRAWINGS">FIG. 3</figref> is a schematic side view of the barrier metal film production apparatus according to the second embodiment of the present invention. <figref idref="DRAWINGS">FIG. 4</figref> is a view taken along the arrowed line IV-IV of <figref idref="DRAWINGS">FIG. 3</figref>. <figref idref="DRAWINGS">FIG. 5</figref> is a view taken along the arrowed line V-V of <figref idref="DRAWINGS">FIG. 4</figref>. The same members as the members illustrated in <figref idref="DRAWINGS">FIG. 1</figref> are assigned the same numerals, and duplicate explanations are omitted.

0409An upper surface of the chamber <b>1</b> is an opening, which is closed with a disk-shaped ceiling board <b>30</b> made of an insulating material (for example, a ceramic). An etched member <b>31</b> made of a metal (e.g., W. Ti, Ta or TiSi) is interposed between the opening at the upper surface of the chamber <b>1</b> and the ceiling board <b>30</b>. The etched member <b>31</b> is provided with a ring portion <b>32</b> fitted into the opening at the upper surface of the chamber <b>1</b>. A plurality of (<b>12</b> in the illustrated embodiment) protrusions <b>33</b>, which extend close to the center in the diametrical direction of the chamber <b>1</b> and have the same width, are provided in the circumferential direction on the inner periphery of the ring portion <b>32</b>.

0410The protrusions <b>33</b> are integrally or removably attached to the ring portion <b>32</b>. Notches (spaces) <b>35</b> formed between the protrusions <b>33</b> are present between the ceiling board <b>30</b> and the interior of the chamber <b>1</b>. The ring portion <b>32</b> is earthed, and the plural protrusions <b>33</b> are electrically connected together and maintained at the same potential. Temperature control means (not shown), such as a heater, is provided in the etched member <b>31</b> to control the temperature of the etched member <b>31</b> to 200 to 400° C., for example.

0411Second protrusions shorter in the diametrical direction than the protrusions <b>33</b> can be arranged between the protrusions <b>33</b>. Moreover, short protrusions can be arranged between the protrusion <b>33</b> and the second protrusion. By so doing, the area of copper, an object to be etched, can be secured, with an induced current being suppressed.

0412A planar winding-shaped plasma antenna <b>34</b>, for converting the atmosphere inside the chamber <b>1</b> into a plasma, is provided above the ceiling board <b>30</b>. The plasma antenna <b>34</b> is formed in a planar ring shape parallel to the surface of the ceiling board <b>30</b>. A matching instrument <b>10</b> and a power source <b>11</b> are connected to the plasma antenna <b>34</b> to supply power. The etched member <b>31</b> has the plurality of protrusions <b>33</b> provided in the circumferential direction on the inner periphery of the ring portion <b>32</b>, and includes the notches (spaces) <b>35</b> formed between the protrusions <b>33</b>. Thus, the protrusions <b>33</b> are arranged between the substrate <b>3</b> and the ceiling board <b>30</b> in a discontinuous state relative to the flowing direction of electricity in the plasma antenna <b>34</b>.

0413With the above-described barrier metal film production apparatus, the source gas is supplied through the nozzles <b>12</b> to the interior of the chamber <b>1</b>, and electromagnetic waves are shot from the plasma antenna <b>34</b> into the chamber <b>1</b>. As a result, the Cl₂gas is ionized to generate a Cl₂gas plasma (source gas plasma) <b>21</b>. The etched member <b>31</b>, an electric conductor, is present below the plasma antenna <b>34</b>. However, the Cl₂gas plasma <b>21</b> occurs stably between the etched member <b>31</b> and the substrate <b>3</b>, namely, below the etched member <b>31</b>, under the following action:

0414The action by which the Cl₂gas plasma <b>21</b> is generated below the etched member <b>31</b> will be described. As shown in <figref idref="DRAWINGS">FIG. 5</figref>, a flow A of electricity in the plasma antenna <b>34</b> of the planar ring shape crosses the protrusions <b>33</b>. At this time, an induced current B occurs on the surface of the protrusion <b>33</b> opposed to the plasma antenna <b>34</b>. Since the notches (spaces) <b>35</b> are present in the etched member <b>31</b>, the induced current B flows onto the lower surface of each protrusion <b>33</b>, forming a flow a in the same direction as the flow A of electricity in the plasma antenna <b>34</b> (Faraday shield).

0415When the etched member <b>31</b> is viewed from the substrate <b>3</b>, therefore, there is no flow in a direction in which the flow A of electricity in the plasma antenna <b>34</b> is canceled out. Furthermore, the ring portion <b>32</b> is earthed, and the protrusions <b>33</b> are maintained at the same potential. Thus, even though the etched member <b>31</b>, an electric conductor, exists, the electromagnetic wave is reliably thrown from the plasma antenna <b>34</b> into the chamber <b>1</b>. Consequently, the Cl₂gas plasma <b>21</b> is stably generated below the etched member <b>31</b>.

0416Furthermore, plasma generation means composed of a passage <b>15</b>, an excitation chamber <b>16</b> and a plasma antenna <b>17</b> is provided above the support platform <b>2</b>.

0417The Cl₂gas plasma <b>21</b> causes an etching reaction to the etched member <b>31</b>, forming a precursor (M_xCl_y: M is a metal such as W, Ti, Ta or TiSi) <b>22</b>. In the excitation chamber <b>16</b>, the NH₃gas is ionized to generate an NH₃gas plasma <b>23</b>. The excited ammonia of the NH₃gas plasma <b>23</b> in the excitation chamber <b>16</b> is fed to the precursor (M_xCl_y) <b>22</b> inside the chamber <b>1</b> through the opening portion <b>14</b>. Because of this construction, the metal component of the precursor (M_xCl_y) <b>22</b> and ammonia react to form a metal nitride (MN) (formation means). At this time, the etched member <b>31</b> and the excitation chamber <b>16</b> are maintained by the plasmas at predetermined temperatures (e.g., 200 to 400° C.) which are higher than the temperature of the substrate <b>3</b>.

0418The metal nitride (MN) formed within the chamber <b>1</b> is transported toward the substrate <b>3</b> controlled to a low temperature, whereby a thin MN film <b>24</b> is formed on the surface of the substrate <b>3</b>. After the thin MN film <b>24</b> is formed, the supply of the NH₃gas and the supply of power to the power source <b>19</b> are cut off. Thus, the precursor (M_xCl_y) <b>22</b> is transported toward the substrate <b>3</b> controlled to a lower temperature than the temperature of the etched member <b>31</b>. The precursor (M_xCl_y) <b>22</b> transported toward the substrate <b>3</b> is converted into only metal (M) ions by a reduction reaction, and directed at the substrate <b>3</b> to form a thin M film <b>25</b> on the thin MN film <b>24</b> on the substrate <b>3</b>. A barrier metal film <b>26</b> is composed of the thin MN film <b>24</b> and the thin M film <b>25</b> (see <figref idref="DRAWINGS">FIG. 2</figref>). The gases and the etching products, which have not been involved in the reactions, are exhausted through an exhaust port <b>27</b>.

0419With the above-described barrier metal film production apparatus, similar to the first embodiment, the metal is formed by plasmas to produce the barrier metal film <b>26</b>. Thus, the barrier metal film <b>26</b> can be formed uniformly to a small thickness. Consequently, the barrier metal film <b>26</b> can be formed highly accurately at a high speed with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate <b>3</b>.

0420In addition, the etched member <b>31</b> has the plurality of protrusions <b>33</b> provided in the circumferential direction on the inner periphery of the ring portion <b>32</b>, and includes the notches (spaces) <b>35</b> formed between the protrusions <b>33</b>. Thus, the induced currents generated in the etched member <b>31</b> flow in the same direction as the flowing direction of electricity in the plasma antenna <b>34</b>, when viewed from the substrate <b>3</b>. Therefore, even though the etched member <b>31</b>, an electric conductor, exists below the plasma antenna <b>34</b>, the electromagnetic waves are reliably thrown from the plasma antenna <b>34</b> into the chamber <b>1</b>. Consequently, the Cl₂gas plasma <b>21</b> can be stably generated below the etched member <b>31</b>.

0421A barrier metal film production apparatus and a barrier metal film production method according to the third embodiment of the present invention will be described with reference to <figref idref="DRAWINGS">FIG. 6</figref>. <figref idref="DRAWINGS">FIG. 6</figref> is a schematic side view of the barrier metal film production apparatus according to the third embodiment of the present invention. The same members as the members illustrated in <figref idref="DRAWINGS">FIGS. 1 and 3</figref> are assigned the same numerals, and duplicate explanations are omitted.

0422The opening of an upper portion of the chamber <b>1</b> is closed with a ceiling board <b>30</b>, for example, made of a ceramic (an insulating material). An etched member <b>41</b> made of a metal (e.g., W, Ti, Ta or TiSi) is provided on a lower surface of the ceiling board <b>30</b>, and the etched member <b>41</b> is of a quadrangular pyramidal shape. Slit-shaped second opening portions <b>42</b> are formed at a plurality of locations (for example, four locations) in the periphery of an upper part of the cylindrical portion of the chamber <b>1</b>, and one end of a tubular second passage <b>43</b> is fixed to the second opening portion <b>42</b>.

0423A tubular second excitation chamber <b>44</b> made of an insulator is provided halfway through the second passage <b>43</b>, and a coiled second plasma antenna <b>45</b> is provided around the second excitation chamber <b>44</b>. The plasma antenna <b>45</b> is connected to a matching instrument <b>48</b> and a power source <b>49</b> to receive power. The second plasma antenna <b>45</b>, the matching instrument <b>48</b> and the power source <b>49</b> constitute plasma generation means.

0424A flow controller <b>46</b> is connected to the other end of the second passage <b>43</b>, and a chlorine-containing source gas (a Cl₂gas diluted with He or Ar to a chlorine concentration of ≦50%, preferably about 10%) is supplied into the passage <b>43</b> via the flow controller <b>46</b>. By shooting electromagnetic waves from the second plasma antenna <b>45</b> into the second excitation chamber <b>44</b>, the Cl₂gas is ionized to generate a Cl₂gas plasma (source gas plasma) <b>47</b> Because of the generation of the Cl₂gas plasma <b>47</b>, excited chlorine is fed into the chamber <b>1</b> through the second opening portion <b>42</b>, whereupon the etched member <b>41</b> is etched with excited chlorine.

0425With the above-described barrier metal film production apparatus, the source gas is supplied into the second passage <b>43</b> via the flow controller <b>46</b> and fed into the second excitation chamber <b>44</b>. By shooting electromagnetic waves from the second plasma antenna <b>45</b> into the second excitation chamber <b>44</b>, the Cl₂gas is ionized to generate a Cl₂gas plasma (source gas plasma) <b>47</b>. Since a predetermined differential pressure has been established between the pressure inside the chamber <b>1</b> and the pressure inside the second excitation chamber <b>44</b> by the vacuum device <b>8</b>, the excited chlorine of the Cl₂gas plasma <b>47</b> in the second excitation chamber <b>44</b> is fed to the etched member <b>41</b> inside the chamber <b>1</b> through the second opening portion <b>42</b>. The excited chlorine causes an etching reaction to the etched member <b>41</b>, forming a precursor (M_xCl_y) <b>22</b> inside the chamber <b>1</b>. At this time, the etched member <b>41</b> is maintained at a predetermined temperature (e.g., 200 to 400° C.), which is higher than the temperature of the substrate <b>3</b>, by a heater <b>50</b> provided in the ceiling board <b>30</b>.

0426In the excitation chamber <b>16</b>, the NH₃gas is ionized to generate an NH₃gas plasma <b>23</b>. The excited ammonia of the NH₃gas plasma <b>23</b> in the excitation chamber <b>16</b> is fed to the precursor (M_xCl_y) <b>22</b> inside the chamber <b>1</b> through the opening portion <b>14</b>. As a result, the metal component of the precursor (M_xCl_y) <b>22</b> and ammonia react to form a metal nitride (MN). At this time, the excitation chamber <b>16</b> is maintained by the plasma at a predetermined temperature (e.g., 200 to 400° C.) which is higher than the temperature of the substrate <b>3</b>.

0427The metal nitride (MN) formed within the chamber <b>1</b> is transported toward the substrate <b>3</b> controlled to a low temperature, whereby a thin MN film <b>24</b> is formed on the surface of the substrate <b>3</b>. After the thin MN film <b>24</b> is formed, the supply of the NH₃gas and the supply of power to the power source <b>19</b> are cut off. Thus, the precursor (M_xCl_y) <b>22</b> is transported toward the substrate <b>3</b> controlled to a lower temperature than the temperature of the etched member <b>41</b>. The precursor (M_xCl_y) <b>22</b> transported toward the substrate <b>3</b> is converted into only metal (M) ions by a reduction reaction, and directed at the substrate <b>3</b> to form a thin M film <b>25</b> on the thin MN film <b>24</b> placed on the substrate <b>3</b>. A barrier metal film <b>26</b> is composed of the thin MN film <b>24</b> and the thin M film <b>25</b> (see <figref idref="DRAWINGS">FIG. 2</figref>). The gases and the etching products that have not been involved in the reactions are exhausted through an exhaust port <b>27</b>.

0428With the above-described barrier metal film production apparatus, similar to the first embodiment and the second embodiment, the metal is formed by plasmas to produce the barrier metal film <b>26</b>. Thus, the barrier metal film <b>26</b> can be formed uniformly to a small thickness. Consequently, the barrier metal film <b>26</b> can be formed highly accurately at a high speed with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate <b>3</b>.

0429Furthermore, the Cl₂gas plasma <b>47</b> is generated in the second excitation chamber <b>44</b> isolated from the chamber <b>1</b>. Thus, the substrate <b>3</b> is not exposed to the plasma any more, and the substrate <b>3</b> becomes free from damage from the plasma.

0430As the means for generating the Cl₂gas plasma <b>47</b> in the second excitation chamber <b>44</b>, namely, the means for exciting the source gas to convert it into an excited source gas, it is possible to use microwaves, laser, electron rays, or synchrotron radiation. It is also permissible to form the precursor by heating the metal filament to a high temperature. The construction for isolating the Cl₂gas plasma <b>47</b> from the substrate <b>3</b> may be the provision of the second excitation chamber <b>44</b> in the passage <b>43</b>, as stated above, or may be other construction, for example, the isolation of the chamber <b>1</b>.

0431A barrier metal film production apparatus and a barrier metal film production method according to the fourth embodiment of the present invention will be described with reference to <figref idref="DRAWINGS">FIG. 7</figref>. <figref idref="DRAWINGS">FIG. 7</figref> is a schematic side view of a barrier metal film production apparatus according to the fourth embodiment of the present invention. The same members as the members illustrated in <figref idref="DRAWINGS">FIG. 1</figref> are assigned the same numerals, and duplicate explanations are omitted.

0432Compared with the barrier metal film production apparatus of the first embodiment shown in <figref idref="DRAWINGS">FIG. 1</figref>, the plasma antenna <b>9</b> is not provided around the cylindrical portion of the chamber <b>1</b>, and the matching instrument <b>10</b> and power source <b>11</b> are connected to the metal member <b>7</b> for supply of power to the metal member <b>7</b>.

0433With the above-described barrier metal film production apparatus, the source gas is supplied from the nozzle <b>12</b> into the chamber <b>1</b>, and electromagnetic waves are shot from the metal member <b>7</b> into the chamber <b>1</b>, whereby the Cl₂gas is ionized to generate a Cl₂gas plasma (source gas plasma) <b>21</b>. The Cl₂gas plasma <b>21</b> causes an etching reaction to the metal member <b>7</b>, forming a precursor (M_xCl_y) <b>22</b>. At this time, the metal member <b>7</b> is maintained at a temperature (e.g., 200 to 400° C.), which is higher than the temperature of the substrate <b>3</b>, by temperature control means (not shown).

0434In the excitation chamber <b>16</b>, the NH₃gas is ionized to generate an NH₃gas plasma <b>23</b>. The excited ammonia of the NH₃gas plasma <b>23</b> in the excitation chamber <b>16</b> is fed to the precursor (M_xCl_y) <b>22</b> inside the chamber <b>1</b> through the opening portion <b>14</b>. As a result, the metal component of the precursor (M_xCl_y) <b>22</b> and ammonia react to form a metal nitride (MN). At this time, the excitation chamber <b>16</b> is maintained by the plasma at a predetermined temperature (e.g., 200 to 400° C.) which is higher than the temperature of the substrate <b>3</b>.

0435The metal nitride (MN) formed within the chamber <b>1</b> is transported toward the substrate <b>3</b> controlled to a low temperature, whereby a thin MN film <b>24</b> is formed on the surface of the substrate <b>3</b>. After the thin MN film <b>24</b> is formed, the supply of the NH₃gas and the supply of power to the power source <b>19</b> are cut off. Thus, the precursor (M_xCl_y) <b>22</b> is transported toward the substrate <b>3</b> controlled to a lower temperature than the temperature of the metal member <b>7</b>. The precursor (M_xCl_y) <b>22</b> transported toward the substrate <b>3</b> is converted into only metal (M) ions by a reduction reaction, and directed at the substrate <b>3</b> to form a thin M film <b>25</b> on the thin MN film <b>24</b> placed on the substrate <b>3</b>. A barrier metal film <b>26</b> is composed of the thin MN film <b>24</b> and the thin M film <b>25</b> (see <figref idref="DRAWINGS">FIG. 2</figref>). The gases and the etching products that have not been involved in the reactions are exhausted through an exhaust port <b>27</b>.

0436With the above-described barrier metal film production apparatus, similar to the first embodiment to the third embodiment, the metal is formed by plasmas to produce the barrier metal film <b>26</b>. Thus, the barrier metal film <b>26</b> can be formed uniformly to a small thickness. Consequently, the barrier metal film <b>26</b> can be formed highly accurately at a high speed with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate <b>3</b>.

0437Furthermore, the metal member <b>7</b> itself is applied as an electrode for plasma generation. Thus, the plasma antenna <b>9</b> need not be provided around the cylindrical portion of the chamber <b>1</b>, and the degree of freedom of the construction in the surroundings can be increased.

0438A barrier metal film production apparatus and a barrier metal film production method according to the fifth embodiment of the present invention will be described with reference to <figref idref="DRAWINGS">FIG. 8</figref>. <figref idref="DRAWINGS">FIG. 8</figref> is a schematic side view of the barrier metal film production apparatus according to the fifth embodiment of the present invention. The same members as the members illustrated in <figref idref="DRAWINGS">FIG. 1</figref> are assigned the same numerals, and duplicate explanations are omitted.

0439Compared with the first embodiment shown in <figref idref="DRAWINGS">FIG. 1</figref>, the barrier metal film production apparatus shown in <figref idref="DRAWINGS">FIG. 8</figref> lacks the opening portion <b>14</b>, passage <b>15</b>, excitation chamber <b>16</b>, plasma antenna <b>17</b>, matching instrument <b>18</b>, power source <b>19</b> and flow controller <b>20</b>. Nozzles <b>12</b> for supplying a gas mixture of a source gas (Cl₂gas) and a nitrogen gas (N₂gas) as a nitrogen-containing gas to the interior of the chamber <b>1</b> are connected to the cylindrical portion of the chamber <b>1</b>. The Cl₂gas and the N₂gas are mixed in a mixed gas flow controller <b>81</b>, and the gas mixture of the Cl₂gas and the N₂gas is supplied to the nozzle <b>12</b> via the mixed gas flow controller <b>81</b>. Other constructions are the same as in the first embodiment.

0440With the above-described barrier metal film production apparatus, the mixed gas comprising the Cl₂gas and the N₂gas is supplied through the nozzles <b>12</b> to the interior of the chamber <b>1</b>, and electromagnetic waves are shot from the plasma antenna <b>9</b> into the chamber <b>1</b>. As a result, the Cl₂gas and the N₂gas are ionized to generate a Cl₂gas/N₂gas plasma <b>82</b>. The Cl₂gas/N₂gas plasma <b>82</b> causes an etching reaction to the metal member <b>7</b>, forming a precursor (M_xCl_y: M is a metal such as W, Ti, Ta or TiSi) <b>22</b>. Also, the precursor <b>22</b> and N₂react to form a metal nitride (MN). At this time, the metal member <b>7</b> is maintained by the plasma (or temperature control means (not shown)) at a predetermined temperature (e.g., 200 to 400° C.) which is higher than the temperature of the substrate <b>3</b>.

0441The metal nitride (MN) formed within the chamber <b>1</b> is transported toward the substrate <b>3</b> controlled to a low temperature, whereby a thin MN film <b>24</b> is formed on the surface of the substrate <b>3</b>. After the thin MN film <b>24</b> is formed, the supply of the N₂gas to the mixed gas flow controller <b>81</b> is cut off. Thus, the precursor (M_xCl_y) <b>22</b> is transported toward the substrate <b>3</b> controlled to a lower temperature than the temperature of the metal member <b>7</b>. The precursor (M_xCl_y) <b>22</b> transported toward the substrate <b>3</b> is converted into only metal (M) ions by a reduction reaction, and directed at the substrate <b>3</b> to form a thin M film <b>25</b> on the surface of the substrate <b>3</b>. A barrier metal film <b>26</b> is composed of the thin MN film <b>24</b> and the thin M film <b>25</b> (see <figref idref="DRAWINGS">FIG. 2</figref>).

0442The substrate <b>3</b>, on which the barrier metal film <b>26</b> has been formed, is to have a thin copper (Cu) film or a thin aluminum (Al) film formed on the barrier metal film <b>26</b> by a film forming device. Because of the presence of the barrier metal film <b>26</b>, there arise advantages, for example, such that the thin MN film <b>24</b> eliminates diffusion of Cu into the substrate <b>3</b>, and the thin M film <b>25</b> ensures adhesion of Cu.

0443If the material to be formed as a film is a material unproblematic in terms of adhesion (e.g., Al), or if it is a metal to which the nitride can retain adhesion, the thin M film <b>25</b> can be omitted from the barrier metal film <b>26</b>.

0444With the above-described barrier metal film production apparatus, the same effects as in the first embodiment are obtained. In addition, the supply line for the gases can be simplified, and the number of the plasma sources can be decreased. Thus, the cost of the product can be reduced.

0445The sixth embodiment of a barrier metal film production apparatus and a barrier metal film production method according to the present invention will be described with reference to <figref idref="DRAWINGS">FIG. 9</figref>. <figref idref="DRAWINGS">FIG. 9</figref> is a schematic side view of the barrier metal film production apparatus according to the sixth embodiment of the present invention. The same members as in the second and fifth embodiments illustrated in <figref idref="DRAWINGS">FIGS. 3 to 5</figref> and <b>8</b> are assigned the same numerals, and duplicate explanations are omitted.

0446Compared with the second embodiment shown in <figref idref="DRAWINGS">FIG. 3</figref>, the barrier metal film production apparatus shown in <figref idref="DRAWINGS">FIG. 9</figref> lacks the opening portion <b>14</b>, passage <b>15</b>, excitation chamber <b>16</b>, plasma antenna <b>17</b>, matching instrument <b>18</b>, power source <b>19</b> and flow controller <b>20</b>. Nozzles <b>12</b> for supplying a gas mixture of a source gas (Cl₂gas) and a nitrogen gas (N₂gas) as a nitrogen-containing gas to the interior of the chamber <b>1</b> are connected to the cylindrical portion of the chamber <b>1</b>. The Cl₂gas and the N₂gas are mixed in a mixed gas flow controller <b>81</b>, and the gas mixture of the Cl₂gas and the N₂gas is supplied to the nozzle <b>12</b> via the mixed gas flow controller <b>81</b>. Other constructions are the same as in the second embodiment.

0447With the above-described barrier metal film production apparatus, the mixed gas comprising the Cl₂gas and the N₂gas is supplied through the nozzles <b>12</b> to the interior of the chamber <b>1</b>, and electromagnetic waves are shot from the plasma antenna <b>34</b> into the chamber <b>1</b>. As a result, the Cl₂gas and the N₂gas are ionized to generate a Cl₂gas /N₂as plasma <b>82</b>. The etched member <b>31</b>, an electric conductor, is present below the plasma antenna <b>34</b>. As stated earlier, however, the Cl₂gas/N₂gas plasma <b>82</b> occurs stably between the etched member <b>31</b> and the substrate <b>3</b>, namely, below the etched member <b>31</b>.

0448The Cl₂gas/N₂gas plasma <b>82</b> causes an etching reaction to the etched member <b>31</b>, forming a precursor (M_xCl_y: M is a metal such as W, Ti, Ta or TiSi) <b>22</b>. Also, the precursor <b>22</b> and N₂react to form a metal nitride (MN). At this time, the etched member <b>31</b> is maintained by the plasma (or temperature control means (not shown)) at a predetermined temperature (e.g., 200 to 400° C.) which is higher than the temperature of the substrate <b>3</b>.

0449The metal nitride (MN) formed within the chamber <b>1</b> is transported toward the substrate <b>3</b> controlled to a low temperature, whereby a thin MN film <b>24</b> is formed on the surface of the substrate <b>3</b>. After the thin MN film <b>24</b> is formed, the supply of the N₂gas to the mixed gas flow controller <b>81</b> is cut off. Thus, the precursor (M_xCl_y) <b>22</b> is transported toward the substrate <b>3</b> controlled to a lower temperature than the temperature of the etched member <b>31</b>. The precursor (M_xCl_y) <b>22</b> transported toward the substrate <b>3</b> is converted into only metal (M) ions by a reduction reaction, and directed at the substrate <b>3</b> to form a thin M film <b>25</b> on the thin MN film <b>24</b> on the substrate <b>3</b>. A barrier metal film <b>26</b> is composed of the thin MN film <b>24</b> and the thin M film <b>25</b> (see <figref idref="DRAWINGS">FIG. 2</figref>).

0450The substrate <b>3</b>, on which the barrier metal film <b>26</b> has been formed, is to have a thin copper (Cu) film or a thin aluminum (Al) film formed on the barrier metal film <b>26</b> by a film forming device. Because of the presence of the barrier metal film <b>26</b>, there arise advantages, for example, such that the thin MN film <b>24</b> eliminates diffusion of Cu into the substrate <b>3</b>, and the thin M film <b>25</b> ensures adhesion of Cu.

0451If the material to be formed as a film is a material unproblematic in terms of adhesion (e.g., Al), or if it is a metal to which the nitride can retain adhesion, the thin M film <b>25</b> can be omitted from the barrier metal film <b>26</b>.

0452With the above-described barrier metal film production apparatus, the same effects as in the second embodiment are obtained. In addition, the supply line for the gases can be simplified, and the number of the plasma sources can be decreased. Thus, the cost of the product can be reduced.

0453The seventh embodiment of a barrier metal film production apparatus and a barrier metal film production method according to the present invention will be described with reference to <figref idref="DRAWINGS">FIG. 10</figref>. <figref idref="DRAWINGS">FIG. 10</figref> is a schematic side view of the barrier metal film production apparatus according to the seventh embodiment of the present invention. The same members as in the third and fifth embodiments illustrated in <figref idref="DRAWINGS">FIGS. 6 and 8</figref> are assigned the same numerals, and duplicate explanations are omitted.

0454Compared with the third embodiment shown in <figref idref="DRAWINGS">FIG. 6</figref>, the barrier metal film production apparatus shown in <figref idref="DRAWINGS">FIG. 10</figref> lacks the opening portion <b>14</b>, passage <b>15</b>, excitation chamber <b>16</b>, plasma antenna <b>17</b>, matching instrument <b>18</b>, power source <b>19</b> and flow controller <b>20</b>. A gas mixture of a source gas (Cl₂gas) and a nitrogen gas (N₂gas) as a nitrogen-containing gas is supplied from a mixed gas flow controller <b>81</b> to a second excitation chamber <b>44</b>. Other constructions are the same as in the third embodiment.

0455With the above-described barrier metal film production apparatus, the mixed gas comprising the Cl₂gas and the N₂gas is supplied into a second passage <b>43</b> via the mixed gas flow controller <b>81</b>, and fed into the second excitation chamber <b>44</b>. Electromagnetic waves are shot from a second plasma antenna <b>45</b> into the second excitation chamber <b>44</b>. As a result, the Cl₂gas and the N₂gas are ionized to generate a Cl₂gas/N₂gas plasma <b>82</b>. Since a predetermined differential pressure has been established between the pressure inside the chamber <b>1</b> and the pressure inside the second excitation chamber <b>44</b> by the vacuum device <b>8</b>, the excited chlorine and excited nitrogen of the Cl₂gas/N₂gas plasma <b>82</b> in the second excitation chamber <b>44</b> are fed to the etched member <b>41</b> inside the chamber <b>1</b> through the second opening portion <b>42</b>. The excited chlorine causes an etching reaction to the etched member <b>41</b>, forming a precursor (M_xCl_y) <b>22</b> inside the chamber <b>1</b>. Also, the precursor <b>22</b> and the excited nitrogen react to form a metal nitride (MN). At this time, the etched member <b>41</b> is maintained at a predetermined temperature (e.g., 200 to 400° C.), which is higher than the temperature of the substrate <b>3</b>, by a heater <b>50</b> provided in a ceiling board <b>30</b>.

0456The metal nitride (MN) formed within the chamber <b>1</b> is transported toward the substrate <b>3</b> controlled to a low temperature, whereby a thin MN film <b>24</b> is formed on the surface of the substrate <b>3</b>. After the thin MN film <b>24</b> is formed, the supply of the N₂gas to the mixed gas flow controller <b>81</b> is cut off. Thus, the precursor (M_xCl_y) <b>22</b> is transported toward the substrate <b>3</b> controlled to a lower temperature than the temperature of the etched member <b>41</b>. The precursor (M_xCl_y) <b>22</b> transported toward the substrate <b>3</b> is converted into only metal (M) ions by a reduction reaction, and directed at the substrate <b>3</b> to form a thin M film <b>25</b> on the thin MN film <b>24</b> on the substrate <b>3</b>. A barrier metal film <b>26</b> is composed of the thin MN film <b>24</b> and the thin M film <b>25</b> (see <figref idref="DRAWINGS">FIG. 2</figref>).

0457The substrate <b>3</b>, on which the barrier metal film <b>26</b> has been formed, is to have a thin copper (Cu) film or a thin aluminum (Al) film formed on the barrier metal film <b>26</b> by a film forming device. Because of the presence of the barrier metal film <b>26</b>, there arise advantages, for example, such that the thin MN film <b>24</b> eliminates diffusion of Cu into the substrate <b>3</b>, and the thin M film <b>25</b> ensures adhesion of Cu.

0458If the material to be formed as a film is a material unproblematic in terms of adhesion (e.g., Al), or if it is a metal to which the nitride can retain adhesion, the thin M film <b>25</b> can be omitted from the barrier metal film <b>26</b>.

0459With the above-described barrier metal film production apparatus, the same effects as in the third embodiment are obtained. In addition, the supply line for the gases can be simplified, and the number of the plasma sources can be decreased. Thus, the cost of the product can be reduced.

0460The eighth embodiment of a barrier metal film production apparatus and a barrier metal film production method according to the present invention will be described with reference to <figref idref="DRAWINGS">FIG. 11</figref>. <figref idref="DRAWINGS">FIG. 11</figref> is a schematic side view of the barrier metal film production apparatus according to the eighth embodiment of the present invention. The same members as in the fourth embodiment and the fifth embodiment illustrated in <figref idref="DRAWINGS">FIGS. 7 and 8</figref> are assigned the same numerals, and duplicate explanations are omitted.

0461Compared with the fourth embodiment shown in <figref idref="DRAWINGS">FIG. 7</figref>, the barrier metal film production apparatus shown in FIG. <b>11</b> lacks the opening portion <b>14</b>, passage <b>15</b>, excitation chamber <b>16</b>, plasma antenna <b>17</b>, matching instrument <b>18</b>, power source <b>19</b> and flow controller <b>20</b>. Nozzles <b>12</b> for supplying a gas mixture of a source gas (Cl₂gas) and a nitrogen gas (N₂gas) as a nitrogen-containing gas to the interior of the chamber <b>1</b> are connected to the cylindrical portion of the chamber <b>1</b>. The Cl₂gas and the N₂gas are mixed in a mixed gas flow controller <b>81</b>, and the gas mixture of the Cl₂gas and the N₂gas is supplied to the nozzle <b>12</b> via the mixed gas flow controller <b>81</b>. Other constructions are the same as in the fourth embodiment.

0462With the above-described barrier metal film production apparatus, the mixed gas comprising the Cl₂gas and the N₂gas is supplied through the nozzles <b>12</b> to the interior of the chamber <b>1</b>, and electromagnetic waves are shot from the metal member <b>7</b> into the chamber <b>1</b>. As a result, the Cl₂gas and the N₂gas are ionized to generate a Cl₂gas/N₂gas plasma <b>82</b>. The Cl₂gas/N₂gas plasma <b>82</b> causes an etching reaction to the metal member <b>7</b>, forming a precursor (M_xCl_y: M is a metal such as W, Ti, Ta or TiSi) <b>22</b>. Also, the precursor <b>22</b> and N₂react to form a metal nitride (MN). At this time, the metal member <b>7</b> is maintained by the plasma (or temperature control means (not shown)) at a predetermined temperature (e.g., 200 to 400° C.) which is higher than the temperature of the substrate <b>3</b>.

0463The metal nitride (MN) formed within the chamber <b>1</b> is transported toward the substrate <b>3</b> controlled to a low temperature, whereby a thin MN film <b>24</b> is formed on the surface of the substrate <b>3</b>. After the thin MN film <b>24</b> is formed, the supply of the N₂gas to the mixed gas flow controller <b>81</b> is cut off. Thus, the precursor (M_xCl_y) <b>22</b> is transported toward the substrate <b>3</b> controlled to a lower temperature than the temperature of the metal member <b>7</b>. The precursor (M_xCl_y) <b>22</b> transported toward the substrate <b>3</b> is converted into only metal (M) ions by a reduction reaction, and directed at the substrate <b>3</b> to form a thin M film <b>25</b> on the thin MN film <b>24</b> on the substrate <b>3</b>. A barrier metal film <b>26</b> is composed of the thin MN film <b>24</b> and the thin M film <b>25</b> (see <figref idref="DRAWINGS">FIG. 2</figref>).

0464The substrate <b>3</b>, on which the barrier metal film <b>26</b> has been formed, is to have a thin copper (Cu) film or a thin aluminum (Al) film formed on the barrier metal film <b>26</b> by a film forming device. Because of the presence of the barrier metal film <b>26</b>, there arise advantages, for example, such that the thin MN film <b>24</b> eliminates diffusion of Cu into the substrate <b>3</b>, and the thin M film <b>25</b> ensures adhesion of Cu.

0465If the material to be formed as a film is a material unproblematic in terms of adhesion (e.g., Al), or if it is a metal to which the nitride can retain adhesion, the thin M film <b>25</b> can be omitted from the barrier metal film <b>26</b>.

0466With the above-described barrier metal film production apparatus, the same effects as in the fourth embodiment are obtained. In addition, the supply line for the gases can be simplified, and the number of the plasma sources can be decreased. Thus, the cost of the product can be reduced.

0467In the foregoing fifth to eighth embodiments, the N₂gas is mixed with the Cl₂gas in the mixed gas flow controller <b>81</b>, and the gas mixture is supplied into the chamber <b>1</b>. However, the N₂gas and the Cl₂gas can be supplied through separate nozzles. Also, ammonia can be applied as the nitrogen-containing gas.

0468The ninth embodiment of the barrier metal film production apparatus and barrier metal film production method of the present invention will be described with reference to <figref idref="DRAWINGS">FIGS. 12 and 18</figref>. <figref idref="DRAWINGS">FIG. 12</figref> is a schematic side view of the barrier metal film production apparatus according to the ninth embodiment of the present invention. <figref idref="DRAWINGS">FIG. 13</figref> shows the sectional status of a substrate illustrating a barrier metal film. <figref idref="DRAWINGS">FIGS. 14 and 15</figref> show the concept status of a barrier metal film in denitrification. <figref idref="DRAWINGS">FIG. 16</figref> shows the concept status of a barrier metal film in oxide layer formation. <figref idref="DRAWINGS">FIG. 17</figref> represents the relationship between the contact angle of copper particles and the oxygen concentration of the substrate. <figref idref="DRAWINGS">FIG. 18</figref> shows the concept status of a barrier metal film in hydroxyl group formation. <figref idref="DRAWINGS">FIG. 19</figref> schematically shows a construction illustrating another example of diluent gas supply means.

0469As shown in <figref idref="DRAWINGS">FIG. 12</figref>, a support platform <b>102</b> is provided near the bottom of a cylindrical chamber <b>101</b> made of, say, a ceramic (an insulating material), and a substrate <b>103</b> is placed on the support platform <b>102</b>. Temperature control means <b>106</b>, as control means, equipped with a heater <b>104</b> and refrigerant flow-through means <b>105</b> is provided in the support platform <b>102</b> so that the support platform <b>102</b> is controlled to a predetermined temperature (for example, a temperature at which the substrate <b>103</b> is maintained at 100 to 200° C.) by the temperature control means <b>106</b>.

0470An upper surface of the chamber <b>101</b> is an opening, which is closed with a metal member <b>107</b>, as an etched member, made of a metal (e.g., W, Ti, Ta, or TiSi). The interior of the chamber <b>101</b> closed with the metal member <b>107</b> is maintained at a predetermined pressure by a vacuum device <b>108</b>. A plasma antenna <b>109</b>, as a coiled winding antenna of plasma generation means, is provided around a cylindrical portion of the chamber <b>101</b>. A matching instrument <b>110</b> and a power source <b>111</b> are connected to the plasma antenna <b>109</b> to supply power.

0471A nozzle <b>112</b>, as source gas supply means, for supplying a source gas (a Cl₂gas diluted with He or Ar to a chlorine concentration of ≦50%, preferably about 10%), containing chlorine as a halogen, to the interior of the chamber <b>101</b> is connected to the cylindrical portion of the chamber <b>101</b> below the metal member <b>107</b>. The nozzle <b>112</b> is fed with the source gas via a flow controller <b>113</b>. The source gas is supplied from the nozzle <b>112</b>, and electromagnetic waves are shot from the plasma antenna <b>109</b> into the chamber <b>101</b>, whereby the Cl₂gas is ionized to generate a Cl₂gas plasma (plasma generation means). Fluorine (F), bromine (Br) or iodine (I) can also be applied as the halogen to be incorporated into the source gas.

0472A nozzle <b>114</b>, as nitrogen-containing gas supply means, for supplying an ammonia gas (NH₃gas) as a nitrogen-containing gas, to the interior of the chamber <b>101</b> is connected to the cylindrical portion of the chamber <b>101</b> below the metal member <b>107</b>. The NH₃gas is supplied from the nozzle <b>114</b>, and electromagnetic waves are shot from the plasma antenna <b>109</b> into the chamber <b>101</b>, whereby the NH₃gas is ionized to generate an NH₃gas plasma (plasma generation means).

0473A diluent gas nozzle <b>121</b> is provided, as diluent gas supply means, for supplying an Ar gas as a diluent gas, to the interior of the chamber <b>101</b> above the surface of the substrate <b>103</b>. The Ar gas is supplied from the diluent gas nozzle <b>121</b>, and electromagnetic waves are shot from the plasma antenna <b>109</b> into the chamber <b>101</b>, whereby the Ar gas is ionized to generate an Ar gas plasma (surface treatment plasma generation means).

0474As described above, the diluent gas supply means applies the Ar gas as the diluent gas for the Cl₂gas. In this case, as shown in <figref idref="DRAWINGS">FIG. 19</figref>, a control valve <b>122</b> may be provided at the site of merger between the source gas (Cl₂gas) and the diluent gas (Ar gas) so that the Cl₂gas is stopped during generation of the Ar gas plasma, and only the Ar gas is supplied through the nozzle <b>112</b>. According to this construction, there is no need for the provision of the diluent gas nozzle <b>121</b>, presenting advantage in space.

0475An oxygen gas nozzle <b>115</b> is provided, as oxygen gas supply means, for supplying an oxygen gas (O₂gas) to the interior of the chamber <b>101</b> above the surface of the substrate <b>103</b>. The O₂gas is supplied from the oxygen gas nozzle <b>115</b>, and electromagnetic waves are shot from the plasma antenna <b>109</b> into the chamber <b>101</b>, whereby the O₂gas is ionized to generate an O₂gas plasma (oxygen plasma generation means).

0476Furthermore, a hydrogen gas nozzle <b>116</b> is provided, as hydrogen gas supply means, for supplying a hydrogen gas (H₂gas) to the interior of the chamber <b>101</b> above the surface of the substrate <b>103</b>. The H₂gas is supplied from the hydrogen gas nozzle <b>116</b>, and electromagnetic waves are shot from the plasma antenna <b>109</b> into the chamber <b>101</b>, whereby the H₂gas is ionized to generate an H₂gas plasma (hydroxyl group plasma generation means).

0477With the above-described barrier metal film production apparatus, the source gas is supplied through the nozzle <b>112</b> to the interior of the chamber <b>101</b>, and electromagnetic waves are shot from the plasma antenna <b>109</b> into the chamber <b>101</b>. As a result, the Cl₂gas is ionized to generate a Cl₂gas plasma (source gas plasma). The Cl₂gas plasma causes an etching reaction to the metal member <b>107</b>, forming a precursor (M_xCl_y: M is a metal such as W, Ti, Ta or TiSi) <b>120</b>. The metal member <b>107</b> is maintained by the plasma at a predetermined temperature (e.g., 200 to 400° C.) which is higher than the temperature of the substrate <b>103</b>.

0478Also, the NH₃gas is supplied into the chamber <b>101</b> through the nozzle <b>114</b>, and electromagnetic waves are shot from the plasma antenna <b>109</b> into the chamber <b>101</b>. Thus, the NH₃gas is ionized to generate an NH₃gas plasma, which causes a reduction reaction with the precursor <b>120</b>, forming a metal nitride (MN). The metal nitride (MN) formed within the chamber <b>101</b> is transported toward the substrate <b>103</b> controlled to a low temperature, whereupon MN is formed into a film on the surface of the substrate <b>103</b> to produce a barrier metal film <b>123</b> (see <figref idref="DRAWINGS">FIG. 13</figref>).

0479The reaction for formation of the barrier metal film <b>123</b> can be expressed by: <br />2MCl+2NH₃→2MN↓+HCl↑+2H₂↑

0480The gases and the etching products that have not been involved in the reaction are exhausted through an exhaust port <b>117</b>.

0481After the barrier metal film <b>1123</b> has been formed, the Ar gas is supplied from the diluent gas nozzle <b>121</b>, and electromagnetic waves are shot from the plasma antenna <b>109</b> into the chamber <b>101</b>, thereby generating an Ar gas plasma. On the surface of the substrate <b>103</b>, the barrier metal film <b>123</b> of MN has been formed, as shown in <figref idref="DRAWINGS">FIG. 14</figref>. Thus, upon generation of the Ar gas plasma, Ar⁺ etches the barrier metal film <b>123</b> on the surface of the substrate <b>103</b>, thereby performing a treatment for removing the nitrogen atoms (N) of the MN in the superficial layer to decrease the nitrogen content of the superficial layer relative to the interior of the matrix of the barrier metal film <b>123</b> (denitrification).

0482As shown in <figref idref="DRAWINGS">FIG. 14</figref>, the barrier metal film <b>123</b> comprises M and N in an amorphous state. In this state, N of a lower mass is preferentially removed by Ar⁺, so that the superficial layer of the barrier metal film <b>123</b> (for example, up to a half, preferably about a third, of the entire film thickness) is denitrified. As a result, there emerges the barrier metal film <b>123</b> of a two-layer structure, a metal layer <b>123</b><i>a </i>substantially composed of M, and an MN layer <b>123</b><i>b</i>, as shown in <figref idref="DRAWINGS">FIG. 15</figref>. On this occasion, the entire film thickness of the barrier metal film <b>123</b> remains the film thickness having the single layer.

0483Immediately before formation of the most superficial layer of the barrier metal film <b>123</b> is completed, a trace amount of O₂gas is supplied through the oxygen gas nozzle <b>115</b> into the chamber <b>101</b>. At the same time, electromagnetic waves are shot from the plasma antenna <b>109</b> into the chamber <b>101</b> to generate an O₂gas plasma. As a result, an oxide layer <b>124</b> is formed on the surface of the metal layer <b>123</b><i>a </i>composed substantially of M, as shown in <figref idref="DRAWINGS">FIG. 16</figref>. Since the oxide layer <b>124</b> has been formed, if a metal (e.g., copper) is deposited (formed as a film) on the surface of the barrier metal film <b>123</b>, wetting with the metal is satisfactory, thus increasing adhesion.

0484In detail, it has been confirmed, as shown in <figref idref="DRAWINGS">FIG. 17</figref>, that the higher the oxygen concentration of the substrate <b>103</b>, the smaller the contact angle θ of a copper particle (the angle that takes minimal surface energy in the presence of a balanced surface tension when the substrate is considered to be a solid and copper is deemed to be a liquid). That is, as the oxygen concentration of the substrate <b>103</b> increases, the copper particle adheres in a collapsed state (a state of high wetting) to the surface of the substrate <b>103</b>. Hence, the O₂gas plasma is generated to form the oxide layer <b>124</b> on the surface of the metal layer <b>123</b><i>a</i>. By so doing, the oxygen concentration of the substrate <b>103</b> can be increased, leading to satisfactory wetting with the metal (copper) to be formed as a film.

0485After formation of the oxide layer <b>124</b> on the surface of the metal layer <b>123</b><i>a</i>, the H₂gas is supplied from the hydrogen gas nozzle <b>116</b> into the chamber <b>101</b>, and electromagnetic waves are shot from the plasma antenna <b>109</b> into the chamber <b>101</b>, thereby generating an H₂gas plasma. As a result, hydroxyl groups (OH groups) are formed on the surface of the oxide layer <b>124</b>, as shown in <figref idref="DRAWINGS">FIG. 18</figref>. These hydroxyl groups increase hydrophilicity, and can further enhance the adhesion of the metal (copper) to be formed as a film.

0486With the above-described barrier metal film production apparatus, the metal is formed by the plasma to produce the barrier metal film <b>123</b>. Thus, the barrier metal film <b>123</b> can be formed uniformly to a small thickness. Consequently, the barrier metal film <b>123</b> can be formed highly accurately at a high speed with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate <b>103</b>.

0487Moreover, denitrification of the barrier metal film <b>123</b> is carried out by removing the nitrogen atoms with the Ar gas plasma. Thus, the barrier metal film <b>123</b> can be granted the two-layer structure, the metal layer <b>123</b><i>a </i>substantially composed of M, and the MN layer <b>123</b><i>b</i>. In addition, the entire film thickness can remain the film thickness constructed from the single layer. Thus, the barrier metal film <b>123</b> can be formed in a two-layer structure without being thickened. Of the two layers, the metal layer <b>123</b><i>a </i>can retain adhesion to a metal to be formed as a film on the surface thereof, while the MN layer (<b>123</b><i>b</i>) can prevent diffusion of the metal. Hence, it becomes possible to produce the barrier metal film which can be formed with good adhesion to the metal to be formed as a film, with diffusion of the metal being eliminated.

0488Besides, the O₂gas plasma is generated to form the oxide layer <b>124</b> on the surface of the metal layer <b>123</b><i>a</i>. Thus, when a metal is formed as a film on the surface of the barrier metal film <b>123</b>, wetting with the metal is satisfactory, and adhesion of the metal can be increased. Additionally, the H₂gas plasma is generated to form hydroxyl groups (OH groups) on the surface of the oxide layer <b>124</b>. Thus, the hydrophilicity improves, and can further increase the adhesion of the metal to be formed as a film.

0489It is permissible to omit the step of generating the H₂gas plasma to form hydroxyl groups (OH groups) on the surface of the oxide layer <b>124</b>. It is also allowable to omit the step of generating the O₂gas plasma to form the oxide layer <b>124</b> on the surface of the metal layer <b>123</b><i>a. </i>

0490The barrier metal film production apparatus and barrier metal film production method according to the tenth embodiment of the present invention will be described with reference to <figref idref="DRAWINGS">FIG. 20</figref>. <figref idref="DRAWINGS">FIG. 20</figref> schematically shows the construction of the barrier metal film production apparatus according to the tenth embodiment of the present invention. The same members as the members shown in <figref idref="DRAWINGS">FIG. 12</figref> are assigned the same numerals, and duplicate explanations are omitted. <figref idref="DRAWINGS">FIG. 21</figref> shows the concept status of an example of production of a barrier metal film by the barrier metal film production apparatus according to the tenth embodiment of the present invention.

0491Compared with the barrier metal film production apparatus of the ninth embodiment shown in <figref idref="DRAWINGS">FIG. 12</figref>, the barrier metal film production apparatus of the tenth embodiment shown in <figref idref="DRAWINGS">FIG. 20</figref> lacks the diluent gas nozzle <b>121</b>. In the ninth embodiment, the Ar gas is supplied from the diluent gas nozzle <b>121</b> to generate an Ar gas plasma. Using the Ar gas plasma, Ar⁺ etches the barrier metal film <b>123</b> on the surface of the substrate <b>103</b>, thereby performing a treatment for removing the nitrogen atoms (N) of the MN in the superficial layer to decrease the nitrogen content of the superficial layer relative to the interior of the matrix of the barrier metal film <b>123</b> (denitrification). In the present tenth embodiment, on the other hand, when denitrification is to be performed, the O₂gas is supplied from the oxygen gas nozzle <b>115</b> to generate an O₂gas plasma. O₂⁺ etches the barrier metal film <b>123</b> on the surface of the substrate <b>103</b>, performing denitrification. After denitrification, the amount of the O₂gas is decreased to form the oxide layer <b>124</b> (see <figref idref="DRAWINGS">FIG. 16</figref>). Other constructions and actions are the same as in the ninth embodiment.

0492The tenth embodiment can decrease the number of the nozzles for supplying the gases, thus bringing advantage in space.

0493In the barrier metal film production apparatus of the tenth embodiment, the O₂gas plasma can be used only for the formation of the oxide layer <b>124</b> (see <figref idref="DRAWINGS">FIG. 16</figref>) without being used for etching. In this case, the barrier metal film <b>123</b> is only the single layer, MN layer <b>123</b><i>b</i>. If the metal to be formed as a film over the substrate <b>103</b> is a metal unproblematic in terms of adhesion (such as Al), for example, the treatment for forming the metal layer <b>123</b><i>a </i>by etching can be omitted.

0494In the barrier metal film production apparatus of the tenth embodiment, moreover, the O₂gas plasma can be used similarly only for the formation of the oxide layer <b>124</b> (see <figref idref="DRAWINGS">FIG. 16</figref>) without being used for etching. In this case, however, after the MN layer <b>123</b><i>b </i>is formed, the supply of the NH₃gas from the nozzle <b>114</b> is cut off to terminate the reaction of the precursor <b>120</b> with an NH₃gas plasma. Then, as shown in <figref idref="DRAWINGS">FIG. 21</figref>, the metal component of the precursor <b>120</b> is superposed on the MN layer <b>123</b><i>b</i>, whereby the meta layer <b>123</b><i>a </i>can be formed.

0495The reaction for formation of the metal layer <b>123</b><i>a </i>from the metal component of the precursor <b>120</b> can be expressed by: <br />2MCl→2M↓+Cl₂↑

0496The barrier metal film production apparatus and barrier metal film production method according to the eleventh embodiment of the present invention will be described with reference to <figref idref="DRAWINGS">FIG. 22</figref>. <figref idref="DRAWINGS">FIG. 22</figref> schematically shows the construction of the barrier metal film production apparatus according to the eleventh embodiment of the present invention. The same members as in the barrier metal film production apparatus shown in <figref idref="DRAWINGS">FIG. 12</figref> are assigned the same numerals, and duplicate explanations are omitted.

0497As shown in <figref idref="DRAWINGS">FIG. 22</figref>, a support platform <b>102</b> is provided near the bottom of a chamber <b>101</b>, and a substrate <b>103</b> is placed on the support platform <b>102</b>. Temperature control means <b>106</b>, as control means, equipped with a heater <b>104</b> and refrigerant flow-through means <b>105</b> is provided in the support platform <b>102</b> so that the support platform <b>102</b> is controlled to a predetermined temperature (for example, a temperature at which the substrate <b>103</b> is maintained at 100 to 200° C.) by the temperature control means <b>106</b>. An upper surface of the chamber <b>101</b> is an opening, which is closed with a metal member <b>107</b> (e.g., W, Ti, Ta, or TiSi). The interior of the chamber <b>101</b> closed with the metal member <b>107</b> is maintained at a predetermined pressure by a vacuum device <b>108</b>. A plasma antenna <b>109</b> is provided around a cylindrical portion of the chamber <b>101</b>. A matching instrument <b>110</b> and a power source <b>111</b> are connected to the plasma antenna <b>109</b> to supply power.

0498A nozzle <b>112</b> for supplying a source gas is connected to the cylindrical portion of the chamber <b>101</b> below the metal member <b>107</b>. The source gas is supplied from the nozzle <b>112</b>, and electromagnetic waves are shot from the plasma antenna <b>109</b> into the chamber <b>101</b>, whereby the Cl₂gas is ionized to generate a Cl₂gas plasma (plasma generation means).

0499A diluent gas nozzle <b>121</b> is provided for supplying an Ar gas to the interior of the chamber <b>101</b>. Also, electromagnetic waves are shot from the plasma antenna <b>109</b> into the chamber <b>101</b>. Thus, the Ar gas is ionized to generate an Ar gas plasma (surface treatment plasma generation means). If an Ar gas is applied as the diluent gas for the Cl₂gas, diluent gas supply means may be constructed, similar to the ninth embodiment, such that only the Ar gas is supplied from the nozzle <b>112</b>.

0500An oxygen gas nozzle <b>115</b> is provided for supplying an oxygen gas (O₂gas) to the interior of the chamber <b>101</b>. Also, electromagnetic waves are shot from the plasma antenna <b>109</b> into the chamber <b>101</b>. Thus, the O₂gas is ionized to generate an O₂gas plasma (oxygen plasma generation means). Moreover, a hydrogen gas nozzle <b>116</b> is provided for supplying a hydrogen gas (H₂gas) to the interior of the chamber <b>101</b>. Also, electromagnetic waves are shot from the plasma antenna <b>109</b> into the chamber <b>101</b>. Thus, the H₂gas is ionized to generate an H₂gas plasma (hydroxyl group plasma generation means).

0501Slit-shaped opening portions <b>131</b> are formed at a plurality of locations (for example, four locations; only one of the locations is shown in the drawing) in the periphery of a lower part of the cylindrical portion of the chamber <b>101</b>, and one end of a tubular passage <b>132</b> is fixed to the opening portion <b>131</b>. A tubular excitation chamber <b>33</b> made of an insulator is provided halfway through the passage <b>132</b>, and a coiled plasma antenna <b>134</b> is provided around the excitation chamber <b>133</b>. The plasma antenna <b>134</b> is connected to a matching instrument <b>135</b> and a power source <b>136</b> to receive power. The plasma antenna <b>134</b>, the matching instrument <b>135</b> and the power source <b>136</b> constitute excitation means. A flow controller <b>137</b> is connected to the other end of the passage <b>132</b>, and an ammonia gas (NH₃gas) as a nitrogen-containing gas is supplied into the passage <b>132</b> via the flow controller <b>137</b>.

0502Separately, the NH₃gas is supplied into the passage <b>132</b> via the flow controller <b>137</b> and fed into the excitation chamber <b>133</b>. By shooting electromagnetic waves from the plasma antenna <b>134</b> into the excitation chamber <b>133</b>, the NH₃gas is ionized to generate an NH₃gas plasma <b>138</b>. Since a predetermined differential pressure has been established between the pressure inside the chamber <b>101</b> and the pressure inside the excitation chamber <b>133</b> by the vacuum device <b>108</b>, the excited ammonia of the NH₃gas plasma <b>138</b> in the excitation chamber <b>133</b> is fed to the precursor (M_xCl_y) <b>120</b> inside the chamber <b>101</b> through the opening portion <b>131</b>.

0503That is, excitation means for exciting the nitrogen-containing gas in the excitation chamber <b>133</b> isolated from the chamber <b>101</b> is constructed. Because of this construction, the metal component of the precursor (M_xCl_y) <b>120</b> and ammonia react to form a metal nitride (MN) (formation means). At this time, the metal member <b>107</b> and the excitation chamber <b>133</b> are maintained by the plasmas at predetermined temperatures (e.g., 200 to 400° C.) which are higher than the temperature of the substrate <b>103</b>.

0504With the above-described barrier metal film production apparatus, the source gas is supplied through the nozzle <b>112</b> to the interior of the chamber <b>101</b>, and electromagnetic waves are shot from the plasma antenna <b>109</b> into the chamber <b>101</b>. As a result, a Cl₂gas plasma (source gas plasma) occurs. The Cl₂gas plasma causes an etching reaction to the metal member <b>107</b>, forming a precursor (M_xCl_y) <b>120</b>. The metal member <b>107</b> is maintained by the plasma at a predetermined temperature (e.g., 200 to 400° C.) which is higher than the temperature of the substrate <b>103</b>.

0505The excited ammonia of the NH₃gas plasma <b>138</b> in the excitation chamber <b>133</b> is fed to the precursor (M_xCl_y) <b>120</b> inside the chamber <b>101</b> through the opening portion <b>131</b>. Thus, a metal nitride (MN) is formed inside the chamber <b>101</b>. The resulting metal nitride (MN) is transported toward the substrate <b>103</b> controlled to a low temperature, whereby a barrier metal film <b>23</b> is formed on the surface of the substrate <b>103</b>. The gases and the etching products, which have not been involved in the reaction, are exhausted through an exhaust port <b>117</b>.

0506After the barrier metal film <b>123</b> is formed, the Ar gas is supplied from the diluent gas nozzle <b>121</b>, and electromagnetic waves are shot from the plasma antenna <b>109</b> into the chamber <b>101</b> to generate an Ar gas plasma. Using the Ar gas plasma, Ar⁺ etches the barrier metal film <b>123</b> on the surface of the substrate <b>103</b>, thereby performing a treatment for removing the nitrogen atoms (N) of the MN in the superficial layer to decrease the nitrogen content of the superficial layer relative to the interior of the matrix of the barrier metal film <b>123</b> (denitrification). As a result, there emerges the barrier metal film <b>123</b> of a two-layer structure, a metal layer <b>123</b><i>a </i>substantially composed of M, and an MN layer <b>123</b><i>b </i>(see <figref idref="DRAWINGS">FIG. 15</figref>).

0507Immediately before formation of the most superficial layer of the barrier metal film <b>123</b> is completed, a trace amount of O₂gas is supplied through the oxygen gas nozzle <b>115</b> into the chamber <b>101</b>. At the same time, electromagnetic waves are shot from the plasma antenna <b>109</b> into the chamber <b>101</b> to generate an O₂gas plasma. As a result, an oxide layer <b>124</b> is formed on the surface of the metal layer <b>123</b><i>a </i>composed substantially of M (see <figref idref="DRAWINGS">FIG. 16</figref>). Since the oxide layer <b>124</b> has been formed, if a metal (e.g., copper) is deposited (formed as a film) on the surface of the barrier metal film <b>123</b>, wetting with the metal is satisfactory, thus increasing adhesion.

0508After formation of the oxide layer <b>124</b> on the surface of the metal layer <b>123</b><i>a</i>, the H₂gas is supplied from the hydrogen gas nozzle <b>116</b> into the chamber <b>101</b>, and electromagnetic waves are shot from the plasma antenna <b>109</b> into the chamber <b>101</b>, thereby generating an H₂gas plasma. As a result, hydroxyl groups (OH groups) are formed on the surface of the oxide layer <b>124</b> (see <figref idref="DRAWINGS">FIG. 18</figref>). These hydroxyl groups increase hydrophilicity, and can further enhance the adhesion of the metal (copper) to be formed as a film.

0509With the above-described barrier metal film production apparatus, the barrier metal film <b>123</b> can be formed at a high speed with excellent burial properties in a very small thickness, as in the ninth embodiment. In addition, the entire film thickness can remain the film thickness constructed from the single layer. In this state, it becomes possible to produce the barrier metal film which can be formed with good adhesion to the metal to be formed as a film, with diffusion of the metal being eliminated.

0510Besides, when a metal is formed as a film on the surface of the barrier metal film <b>123</b>, wetting with the metal is satisfactory, and adhesion of the metal can be increased. Additionally, the hydrophilicity improves, and can further increase the adhesion of the metal to be formed as a film.

0511Further, the NH₃gas plasma <b>138</b> is generated in the excitation chamber <b>133</b> isolated from the chamber <b>101</b>. Thus, the influence of the NH₃gas plasma <b>138</b> is not exerted on the surface of the substrate <b>103</b>.

0512It is permissible to omit the step of generating the H₂gas plasma to form hydroxyl groups (OH groups) on the surface of the oxide layer <b>124</b>. It is also allowable to omit the step of generating the O₂gas plasma to form the oxide layer <b>124</b> on the surface of the metal layer <b>123</b><i>a. </i>

0513The barrier metal film production apparatus according to the eleventh embodiment shown in <figref idref="DRAWINGS">FIG. 22</figref> may have a construction in which the diluent gas nozzle <b>121</b> is not provided. In the eleventh embodiment, the Ar gas is supplied from the diluent gas nozzle <b>121</b> to generate an Ar gas plasma. Ar⁺ etches the barrier metal film <b>123</b> on the surface of the substrate <b>103</b>, thereby removing the nitrogen atoms (N) of the MN in the superficial layer to decrease the nitrogen content of the superficial layer relative to the interior of the matrix of the barrier metal film <b>123</b> (denitrification). When denitrification is to be performed, the O₂gas is supplied from the oxygen gas nozzle <b>115</b> to generate an O₂gas plasma, and O₂⁺ etches the barrier metal film <b>123</b> on the surface of the substrate <b>103</b>, thereby carrying out denitrification. After denitrification, the amount of the O₂gas is decreased to form the oxide layer <b>124</b> (see <figref idref="DRAWINGS">FIG. 16</figref>).

0514In this case, the number of the nozzles for supplying the gases can be decreased, thus bringing advantage in space.

0515The O₂gas plasma can be used only for the formation of the oxide layer <b>124</b> (see <figref idref="DRAWINGS">FIG. 16</figref>) without being used for etching. In this case, the barrier metal film <b>123</b> is only the single layer, MN layer <b>123</b><i>b</i>. If the metal to be formed as a film over the substrate <b>103</b> is a metal unproblematic in terms of adhesion (such as Al), for example, the treatment for forming the metal layer <b>123</b><i>a </i>by etching can be omitted.

0516Moreover, the O₂gas plasma can be used similarly only for the formation of the oxide layer <b>124</b> (see <figref idref="DRAWINGS">FIG. 16</figref>) without being used for etching. After the MN layer <b>123</b><i>b </i>is formed, the supply of the NH₃gas and the supply of power to the power source <b>136</b> may be cut off. As a result, the precursor (M_xCl_y) <b>120</b> is transported toward the substrate <b>103</b> controlled to a lower temperature than the temperature of the metal member <b>107</b>. The precursor (M_xCl_y) <b>120</b> transported toward the substrate <b>103</b> is converted into only metal (M) ions by a reduction reaction, and directed at the substrate <b>3</b>. Thus, the metal layer <b>123</b><i>a </i>is superposed on the MN layer <b>123</b><i>b </i>of the substrate <b>103</b>. In this manner, the metal layer <b>123</b><i>a </i>can be formed (see <figref idref="DRAWINGS">FIG. 21</figref>).

0517A barrier metal film production apparatus and a barrier metal film production method according to a twelfth embodiment of the present invention will be described with reference to <figref idref="DRAWINGS">FIGS. 23 to 25</figref>. <figref idref="DRAWINGS">FIG. 23</figref> is a schematic side view of the barrier metal film production apparatus according to the twelfth embodiment of the present invention. <figref idref="DRAWINGS">FIG. 24</figref> is a view taken along the arrowed line XIII-XIII of <figref idref="DRAWINGS">FIG. 23</figref>. <figref idref="DRAWINGS">FIG. 25</figref> is a view taken along the arrowed line XIV-XIV of <figref idref="DRAWINGS">FIG. 24</figref>. The same members as the members illustrated in <figref idref="DRAWINGS">FIGS. 12 to 22</figref> are assigned the same numerals, and duplicate explanations are omitted.

0518An upper surface of the chamber <b>101</b> is an opening, which is closed with a disk-shaped ceiling board <b>141</b> made of an insulating material (for example, a ceramic). An etched member <b>142</b> made of a metal (e.g., W, Ti, Ta or TiSi) is interposed between the opening at the upper surface of the chamber <b>101</b> and the ceiling board <b>141</b>. The etched member <b>142</b> is provided with a ring portion <b>143</b> fitted to the opening at the upper surface of the chamber <b>101</b>. A plurality of (<b>12</b> in the illustrated embodiment) protrusions <b>144</b>, which extend close to the center in the diametrical direction of the chamber <b>101</b> and have the same width, are provided in the circumferential direction on the inner periphery of the ring portion <b>143</b>.

0519The protrusions <b>144</b> are integrally or removably attached to the ring portion <b>143</b>. Notches (spaces) <b>145</b> formed between the protrusions <b>144</b> are present between the ceiling board <b>141</b> and the interior of the chamber <b>101</b>. The ring portion <b>143</b> is earthed, and the plural protrusions <b>144</b> are electrically connected together and maintained at the same potential. Temperature control means (not shown), such as a heater, is provided in the etched member <b>142</b> to control the temperature of the etched member <b>142</b> to 200 to 400° C., for example.

0520Second protrusions shorter in the diametrical direction than the protrusions <b>144</b> can be arranged between the protrusions <b>144</b>. Moreover, short protrusions can be arranged between the protrusion <b>144</b> and the second protrusion. By so doing, the area of the etched member, an object to be etched, can be secured, with an induced current being suppressed.

0521A planar winding-shaped plasma antenna <b>146</b>, for converting the atmosphere inside the chamber <b>101</b> into a plasma, is provided above the ceiling board <b>141</b>. The plasma antenna <b>146</b> is formed in a planar ring shape parallel to the surface of the ceiling board <b>141</b>. A matching instrument <b>110</b> and a power source <b>111</b> are connected to the plasma antenna <b>146</b> to supply power. The etched member <b>142</b> has the plurality of protrusions <b>144</b> provided in the circumferential direction on the inner periphery of the ring portion <b>143</b>, and includes the notches (spaces) <b>145</b> formed between the protrusions <b>144</b>. Thus, the protrusions <b>144</b> are arranged between the substrate <b>103</b> and the ceiling board <b>141</b> in a discontinuous state relative to the flowing direction of electricity in the plasma antenna <b>146</b>.

0522At a cylindrical portion of the chamber <b>101</b>, there are provided a nozzle <b>112</b> for supplying a source gas into the chamber <b>101</b>, a nozzle <b>114</b> for supplying an NH₃gas into the chamber <b>101</b>, a diluent gas nozzle <b>121</b> for supplying an Ar gas into the chamber <b>101</b>, an oxygen gas nozzle <b>115</b> for supplying an O₂gas into the chamber <b>101</b>, and a hydrogen gas nozzle <b>116</b> for supplying an H₂gas into the chamber <b>101</b>.

0523With the above-described barrier metal film production apparatus, the source gas is supplied through the nozzles <b>112</b> to the interior of the chamber <b>101</b>, and electromagnetic waves are shot from the plasma antenna <b>146</b> into the chamber <b>101</b>. As a result, the Cl₂gas is ionized to generate a Cl₂gas plasma (source gas plasma). The etched member <b>142</b>, an electric conductor, is present below the plasma antenna <b>146</b>. However, the Cl₂gas plasma occurs stably between the etched member <b>142</b> and the substrate <b>103</b>, namely, below the etched member <b>142</b>, under the following action:

0524The action by which the Cl₂gas plasma is generated below the etched member <b>142</b> will be described. As shown in <figref idref="DRAWINGS">FIG. 25</figref>, a flow A of electricity in the plasma antenna <b>146</b> of the planar ring shape crosses the protrusions <b>144</b>. At this time, an induced current B occurs on the surface of the protrusion <b>144</b> opposed to the plasma antenna <b>146</b>. Since the notches (spaces) <b>145</b> are present in the etched member <b>142</b>, the induced current B flows onto the lower surface of each protrusion <b>144</b>, forming a flow a in the same direction as the flow A of electricity in the plasma antenna <b>146</b> (Faraday shield).

0525When the etched member <b>142</b> is viewed from the substrate <b>103</b>, therefore, there is no flow in a direction in which the flow A of electricity in the plasma antenna <b>146</b> is canceled out. Furthermore, the ring portion <b>143</b> is earthed, and the protrusions <b>144</b> are maintained at the same potential. Thus, even though the etched member <b>142</b>, an electric conductor, exists, the electromagnetic wave is reliably thrown from the plasma antenna <b>146</b> into the chamber <b>101</b>. Consequently, the Cl₂gas plasma is stably generated below the etched member <b>142</b>.

0526The Cl₂gas plasma causes an etching reaction to the etched member <b>142</b>, forming a precursor (M_xCl_y: M is a metal such as W, Ti, Ta or TiSi) <b>120</b>.

0527Separately, the NH₃gas is supplied into the chamber <b>101</b> through the nozzle <b>114</b>, and electromagnetic waves are shot from the plasma antenna <b>146</b> into the chamber <b>101</b>. Thus, the NH₃gas is ionized to generate an NH₃gas plasma, which causes a reduction reaction with the precursor <b>120</b>, forming a metal nitride (MN). The metal nitride (MN) formed within the chamber <b>101</b> is transported toward the substrate <b>103</b> controlled to a low temperature, whereupon MN is formed into a film on the surface of the substrate <b>103</b> to produce a barrier metal film <b>123</b> (see <figref idref="DRAWINGS">FIG. 13</figref>).

0528After the barrier metal film <b>123</b> has been formed, the Ar gas is supplied from the diluent gas nozzle <b>121</b>, and electromagnetic waves are shot from the plasma antenna <b>146</b> into the chamber <b>101</b>, thereby generating an Ar gas plasma. Generation of the Ar gas plasma results in the etching of the barrier metal film <b>123</b> on the surface of the substrate <b>103</b>, thereby performing denitrification, a treatment for removing the nitrogen atoms (N) of the MN in the superficial layer of the barrier metal film <b>123</b> to decrease the nitrogen content of the superficial layer relative to the interior of the matrix of the barrier metal film <b>123</b>.

0529Immediately before formation of the most superficial layer of the barrier metal film <b>123</b> is completed, a trace amount of O₂gas is supplied through the oxygen gas nozzle <b>115</b> into the chamber <b>101</b>. At the same time, electromagnetic waves are shot from the plasma antenna <b>146</b> into the chamber <b>101</b> to generate an O₂gas plasma. As a result, an oxide layer <b>124</b> (see <figref idref="DRAWINGS">FIG. 16</figref>) is formed on the surface of the metal layer <b>123</b><i>a </i>composed substantially of M (see <figref idref="DRAWINGS">FIG. 16</figref>). Since the oxide layer <b>124</b> has been formed, if a metal (e.g., copper) is deposited (formed as a film) on the surface of the barrier metal film <b>123</b>, wetting with the metal is satisfactory, thus increasing adhesion.

0530After formation of the oxide layer <b>124</b> (see <figref idref="DRAWINGS">FIG. 16</figref>) on the surface of the metal layer <b>123</b><i>a </i>(<figref idref="DRAWINGS">FIG. 16</figref>), the H₂gas is supplied from the hydrogen gas nozzle <b>116</b> into the chamber <b>101</b>, and electromagnetic waves are shot from the plasma antenna <b>146</b> into the chamber <b>101</b>, thereby generating an H₂gas plasma. As a result, hydroxyl groups (OH groups) are formed on the surface of the oxide layer <b>124</b> (see <figref idref="DRAWINGS">FIG. 18</figref>). These hydroxyl groups increase hydrophilicity, and can further enhance the adhesion of the metal (copper) to be formed as a film.

0531It is permissible to omit the step of generating the H₂gas plasma to form hydroxyl groups (OH groups) on the surface of the oxide layer <b>124</b> (see <figref idref="DRAWINGS">FIG. 18</figref>). It is also allowable to omit the step of generating the O₂gas plasma to form the oxide layer <b>124</b> (<figref idref="DRAWINGS">FIG. 16</figref>) on the surface of the metal layer <b>123</b><i>a </i>(<figref idref="DRAWINGS">FIG. 16</figref>). Furthermore, it is possible to superpose the metal layer <b>123</b><i>a</i>, forming the barrier metal film <b>123</b>. It is also possible to form the barrier metal film <b>123</b> free from the metal layer <b>123</b><i>a. </i>

0532Beside, the same nozzle construction as in the tenth embodiment (see <figref idref="DRAWINGS">FIG. 20</figref>) omitting the diluent gas nozzle <b>121</b> may be adopted in a configuration for formation of the precursor <b>120</b> with the exception of the etched member <b>142</b> and the plasma antenna <b>146</b>. Moreover, the same construction as in the eleventh embodiment (see <figref idref="DRAWINGS">FIG. 22</figref>) having the excitation chamber <b>133</b>, etc. instead of the nozzle <b>114</b> may be adopted in a configuration excepting the etched member <b>142</b> and the plasma antenna <b>146</b>.

0533With the above-described barrier metal film production apparatus, the barrier metal film <b>123</b> can be formed uniformly to a small thickness. Consequently, the barrier metal film <b>123</b> can be formed highly accurately at a high speed with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate <b>103</b>.

0534In addition, the etched member <b>142</b> has the plurality of protrusions <b>144</b> provided in the circumferential direction on the inner periphery of the ring portion <b>143</b>, and includes the notches (spaces) <b>145</b> formed between the protrusions <b>144</b>. Thus, the induced currents generated in the etched member <b>142</b> flow in the same direction as the flowing direction of electricity in the plasma antenna <b>146</b>, when viewed from the substrate <b>103</b>. Therefore, even though the etched member <b>142</b>, an electric conductor, exists below the plasma antenna <b>146</b>, the electromagnetic waves are reliably thrown from the plasma antenna <b>146</b> into the chamber <b>101</b>. Consequently, the Cl₂gas plasma can be stably generated below the etched member <b>142</b>.

0535A barrier metal film production apparatus and a barrier metal film production method according to the thirteenth embodiment of the present invention will be described with reference to <figref idref="DRAWINGS">FIG. 26</figref>. <figref idref="DRAWINGS">FIG. 26</figref> is a schematic side view of a barrier metal film production apparatus according to the third embodiment of the present invention. The same members as the members illustrated in <figref idref="DRAWINGS">FIGS. 12 to 25</figref> are assigned the same numerals, and duplicate explanations are omitted.

0536The opening of an upper portion of a chamber <b>101</b> is closed with a ceiling board <b>141</b>. An etched member <b>148</b> made of a metal (e.g., W, Ti, Ta or TiSi) is provided on a lower surface of the ceiling board <b>141</b>, and the etched member <b>148</b> is of a quadrangular pyramidal shape. Slit-shaped opening portions <b>151</b> are formed at a plurality of locations (for example, four locations; one of the locations is shown in the drawing) in the periphery of an upper part of the cylindrical portion of the chamber <b>101</b>, and one end of a tubular passage <b>152</b> is fixed to the opening portion <b>151</b>. A tubular excitation chamber <b>153</b> made of an insulator is provided halfway through the passage <b>152</b>, and a coiled plasma antenna <b>154</b> is provided around the excitation chamber <b>153</b>. The plasma antenna <b>154</b> is connected to a matching instrument <b>157</b> and a power source <b>158</b> to receive power.

0537A flow controller <b>155</b> is connected to the other end of the passage <b>152</b>, and a chlorine-containing source gas (a Cl₂gas diluted with He or Ar to a chlorine concentration of ≦50%, preferably about 10%) is supplied into the passage <b>152</b> via the flow controller <b>155</b>. By shooting electromagnetic waves from the plasma antenna <b>154</b> into the excitation chamber <b>153</b>, the Cl₂gas is ionized to generate a Cl₂gas plasma (source gas plasma) <b>156</b>. Because of the generation of the Cl₂gas plasma <b>156</b>, excited chlorine is fed into the chamber <b>101</b> through the opening portion <b>151</b>, whereupon the etched member <b>148</b> is etched with excited chlorine.

0538At a cylindrical portion of the chamber <b>101</b>, there are provided a nozzle <b>114</b> for supplying an NH₃gas into the chamber <b>101</b>, a diluent gas nozzle <b>121</b> for supplying an Ar gas into the chamber <b>101</b>, an oxygen gas nozzle <b>115</b> for supplying an O₂gas into the chamber <b>101</b>, and a hydrogen gas nozzle <b>116</b> for supplying an H₂gas into the chamber <b>101</b>. Around the chamber <b>101</b>, a plasma antenna <b>109</b>, a matching instrument <b>110</b> and a power source <b>111</b> are provided to generate an NH₃gas plasma, an Ar gas plasma, an O₂gas plasma, and an H₂gas plasma.

0539With the above-described barrier metal film production apparatus, the source gas is supplied into the passage <b>152</b> via the flow controller <b>155</b> and fed into the excitation chamber <b>153</b>. By shooting electromagnetic waves from the plasma antenna <b>154</b> into the excitation chamber <b>153</b>, the Cl₂gas is ionized to generate a Cl₂gas plasma (source gas plasma) <b>156</b>. Since a predetermined differential pressure has been established between the pressure inside the chamber <b>101</b> and the pressure inside the excitation chamber <b>153</b> by the vacuum device <b>108</b>, the excited chlorine of the Cl₂gas plasma <b>156</b> in the excitation chamber <b>153</b> is fed to the etched member <b>148</b> inside the chamber <b>101</b> through the opening portion <b>151</b>. The excited chlorine causes an etching reaction to the etched member <b>148</b>, forming a precursor <b>120</b> inside the chamber <b>101</b>. At this time, the etched member <b>148</b> is maintained at a predetermined temperature (e.g., 200 to 400° C.), which is higher than the temperature of the substrate <b>103</b>, by a heater <b>150</b> provided in the ceiling board <b>141</b>.

0540Separately, the NH₃gas is supplied into the chamber <b>101</b> through the nozzle <b>114</b>, and electromagnetic waves were shot from the plasma antenna <b>109</b> into the chamber <b>101</b>. Thus, the NH₃gas is ionized to generate an NH₃gas plasma, which causes a reduction reaction with the precursor <b>120</b>, forming a metal nitride (MN). The metal nitride (MN) formed within the chamber <b>101</b> is transported toward the substrate <b>103</b> controlled to a low temperature, whereupon MN is formed into a film on the surface of the substrate <b>103</b> to produce a barrier metal film <b>123</b> (see <figref idref="DRAWINGS">FIG. 13</figref>).

0541After the barrier metal film <b>123</b> has been formed, the Ar gas is supplied from the diluent gas nozzle <b>121</b>, and electromagnetic waves are shot from the plasma antenna <b>109</b> into the chamber <b>101</b>, thereby generating an Ar gas plasma. Generation of the Ar gas plasma results in the etching of the barrier metal film <b>123</b> on the surface of the substrate <b>103</b>, thereby performing denitrification, a treatment for removing the nitrogen atoms (N) of the MN in the superficial layer of the barrier metal film <b>123</b> to decrease the nitrogen content of the superficial layer relative to the interior of the matrix of the barrier metal film <b>123</b>.

0542Immediately before formation of the most superficial layer of the barrier metal film <b>123</b> is completed, a trace amount of O₂gas is supplied through the oxygen gas nozzle <b>115</b> into the chamber <b>101</b>. At the same time, electromagnetic waves are shot from the plasma antenna <b>109</b> into the chamber <b>101</b> to generate an O₂gas plasma. As a result, an oxide layer <b>124</b> (see <figref idref="DRAWINGS">FIG. 16</figref>) is formed on the surface of the metal layer <b>123</b><i>a </i>composed substantially of M (see <figref idref="DRAWINGS">FIG. 16</figref>). Since the oxide layer <b>124</b> has been formed, if a metal (e.g., copper) is deposited (formed as a film) on the surface of the barrier metal film <b>123</b>, wetting with the metal is satisfactory, thus increasing adhesion.

0543After formation of the oxide layer <b>124</b> (see <figref idref="DRAWINGS">FIG. 16</figref>) on the surface of the metal layer <b>123</b><i>a </i>(<figref idref="DRAWINGS">FIG. 16</figref>), the H₂gas is supplied from the hydrogen gas nozzle <b>116</b> into the chamber <b>101</b>, and electromagnetic waves are shot from the plasma antenna <b>109</b> into the chamber <b>101</b>, thereby generating an H₂gas plasma. As a result, hydroxyl groups (OH groups) are formed on the surface of the oxide layer <b>124</b> (see <figref idref="DRAWINGS">FIG. 18</figref>). These hydroxyl groups increase hydrophilicity, and can further enhance the adhesion of the metal (copper) to be formed as a film.

0544It is permissible to omit the step of generating the H₂gas plasma to form hydroxyl groups. (OH groups) on the surface of the oxide layer <b>124</b> (see <figref idref="DRAWINGS">FIG. 18</figref>). It is also allowable to omit the step of generating the O₂gas plasma to form the oxide layer <b>124</b> (<figref idref="DRAWINGS">FIG. 16</figref>) on the surface of the metal layer <b>123</b><i>a </i>(<figref idref="DRAWINGS">FIG. 16</figref>). Furthermore, it is possible to superpose the metal layer <b>123</b><i>a</i>, forming the barrier metal film <b>123</b>. It is also possible to form the barrier metal film <b>123</b> free from the metal layer <b>123</b><i>a. </i>

0545Beside, the same nozzle construction as in the tenth embodiment (see <figref idref="DRAWINGS">FIG. 20</figref>) omitting the diluent gas nozzle <b>121</b> may be adopted in a configuration for formation of the precursor <b>120</b> with the exception of the etched member <b>148</b>, opening portion <b>151</b>, passage <b>152</b>, excitation chamber <b>153</b>, plasma antenna <b>154</b>, flow controller <b>155</b>, matching instrument <b>157</b>, and power source <b>158</b>. Moreover, the same construction as in the eleventh embodiment (see <figref idref="DRAWINGS">FIG. 22</figref>) having the excitation chamber <b>133</b>, etc. instead of the nozzle <b>114</b> may be adopted in other configuration for formation of the precursor <b>120</b>.

0546With the above-described barrier metal film production apparatus, the barrier metal film <b>123</b> can be formed uniformly to a small thickness. Consequently, the barrier metal film <b>123</b> can be formed highly accurately at a high speed with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate <b>103</b>.

0547Furthermore, the Cl₂gas plasma <b>156</b> is generated in the excitation chamber <b>153</b> isolated from the chamber <b>101</b>. Thus, the substrate <b>103</b> is not exposed to the Cl₂gas plasma <b>156</b> any more, and the substrate <b>103</b> becomes free from damage from the Cl₂gas plasma <b>156</b>.

0548As the means for generating the Cl₂gas plasma <b>156</b> in the excitation chamber <b>153</b>, namely, the means for exciting the source gas to convert it into an excited source gas, it is possible to use microwaves, laser, electron rays, or synchrotron radiation. It is also permissible to form the precursor by heating the metal filament to a high temperature. The construction for isolating the Cl₂gas plasma <b>156</b> from the substrate <b>103</b> may be the provision of the excitation chamber <b>153</b> in the passage <b>152</b>, or may be other construction, for example, the isolation of the chamber <b>101</b>.

0549A barrier metal film production apparatus and a barrier metal film production method according to the fourteenth embodiment of the present invention will be described with reference to <figref idref="DRAWINGS">FIG. 27</figref>. <figref idref="DRAWINGS">FIG. 27</figref> is a schematic side view of the barrier metal film production apparatus according to the fourteenth embodiment of the present invention. The same members as the members illustrated in <figref idref="DRAWINGS">FIGS. 12 to 26</figref> are assigned the same numerals, and duplicate explanations are omitted.

0550In the barrier metal film production apparatus according to the fourteenth embodiment, unlike the barrier metal film production apparatus according to the ninth embodiment shown in <figref idref="DRAWINGS">FIG. 12</figref>, the plasma antenna <b>9</b> is not provided around the cylindrical portion of the chamber <b>101</b>, but a metal member <b>107</b> is connected to a matching instrument <b>110</b> and a power source <b>111</b> to receive power.

0551At the cylindrical portion of the chamber <b>101</b>, there are provided a nozzle <b>114</b> for supplying an NH₃gas into the chamber <b>101</b>, a diluent gas nozzle <b>121</b> for supplying an. Ar gas into the chamber <b>101</b>, an oxygen gas nozzle <b>115</b> for supplying an O₂gas into the chamber <b>101</b>, and a hydrogen gas nozzle <b>116</b> for supplying an H₂gas into the chamber <b>101</b>. By supplying power to the metal member <b>107</b>, an NH₃gas plasma, an Ar gas plasma, an O₂gas plasma, and an H₂gas plasma are generated. To generate the NH₃gas plasma, Ar gas plasma, O₂gas plasma, and H₂gas plasma, a coiled plasma antenna may be provided separately on the cylindrical portion of the chamber <b>101</b>, and the plasma antenna may be connected to a power source via a matching instrument.

0552With the above-described barrier metal film production apparatus, the source gas is supplied from the nozzle <b>112</b> into the chamber <b>101</b>, and electromagnetic waves are shot from the metal member <b>107</b> into the chamber <b>101</b>, whereby the Cl₂gas is ionized to generate a Cl₂gas plasma (source gas plasma). The Cl₂gas plasma causes an etching reaction to the metal member <b>107</b>, producing a precursor (M_xCl_y) <b>120</b>. At this time, the metal member <b>107</b> is maintained at a predetermined temperature (e.g., 200 to 400° C.), which is higher than the temperature of the substrate <b>103</b>, by temperature control means (not shown).

0553Separately, the NH₃gas is supplied into the chamber <b>101</b> through the nozzle <b>114</b>, and electromagnetic waves are shot from the metal member <b>107</b> into the chamber <b>101</b>. Thus, the NH₃gas is ionized to generate an NH₃gas plasma, which causes a reduction reaction with the precursor <b>120</b>, forming a metal nitride (MN). The metal nitride (MN) formed within the chamber <b>101</b> is transported toward the substrate <b>103</b> controlled to a low temperature, whereupon MN is formed into a film on the surface of the substrate <b>103</b> to produce a barrier metal film <b>123</b> (see <figref idref="DRAWINGS">FIG. 13</figref>).

0554After the barrier metal film <b>123</b> has been formed, the Ar gas is supplied from the diluent gas nozzle <b>121</b>, and electromagnetic waves are shot from the metal member <b>107</b> into the chamber <b>101</b>, thereby generating an Ar gas plasma. Generation of the Ar gas plasma results in the etching of the barrier metal film <b>123</b> on the surface of the substrate <b>103</b>, thereby performing denitrification, a treatment for removing the nitrogen atoms (N) of the MN in the superficial layer of the barrier metal film <b>123</b> to decrease the nitrogen content of the superficial layer relative to the interior of the matrix of the barrier metal film <b>123</b>.

0555Immediately before formation of the most superficial layer of the barrier metal film <b>123</b> is completed, a trace amount of O₂gas is supplied through the oxygen gas nozzle <b>115</b> into the chamber <b>101</b>. At the same time, electromagnetic waves are shot from the metal member <b>107</b> into the chamber <b>101</b> to generate an O₂gas plasma. As a result, an oxide layer <b>124</b> (see <figref idref="DRAWINGS">FIG. 16</figref>) is formed on the surface of a metal layer <b>123</b><i>a </i>composed substantially of M (see <figref idref="DRAWINGS">FIG. 16</figref>). Since the oxide layer <b>124</b> has been formed, if a metal (e.g., copper) is deposited (formed as a film) on the surface of the barrier metal film <b>123</b>, wetting with the metal is satisfactory, thus increasing adhesion.

0556After formation of the oxide layer <b>124</b> (see <figref idref="DRAWINGS">FIG. 16</figref>) on the surface of the metal layer <b>123</b><i>a </i>(<figref idref="DRAWINGS">FIG. 16</figref>), the H₂gas is supplied from the hydrogen gas nozzle <b>116</b> into the chamber <b>101</b>, and electromagnetic waves are shot from the metal member <b>107</b> into the chamber <b>101</b>, thereby generating an H₂gas plasma. As a result, hydroxyl groups (OH groups) are formed on the surface of the oxide layer <b>124</b> (see <figref idref="DRAWINGS">FIG. 18</figref>). These hydroxyl groups increase hydrophilicity, and can further enhance the adhesion of the metal (copper) to be formed as a film.

0557It is permissible to omit the step of generating the H₂gas plasma to form hydroxyl groups (OH groups) on the surface of the oxide layer <b>124</b> (see <figref idref="DRAWINGS">FIG. 18</figref>). It is also allowable to omit the step of generating the O₂gas plasma to form the oxide layer <b>124</b> (<figref idref="DRAWINGS">FIG. 16</figref>) on the surface of the metal layer <b>123</b><i>a </i>(<figref idref="DRAWINGS">FIG. 16</figref>). Furthermore, it is possible to superpose the metal layer <b>123</b><i>a</i>, forming the barrier metal film <b>123</b>. It is also possible to form the barrier metal film <b>123</b> free from the metal layer <b>123</b><i>a. </i>

0558Beside, the same nozzle construction as in the tenth embodiment (see <figref idref="DRAWINGS">FIG. 20</figref>) omitting the diluent gas nozzle <b>121</b> may be adopted in the configuration for formation of the precursor <b>120</b> with the exception of the metal member <b>107</b>, matching instrument <b>110</b>, and power source <b>111</b>. Moreover, the same construction as in the eleventh embodiment (see <figref idref="DRAWINGS">FIG. 22</figref>) having the excitation chamber <b>133</b>, etc. instead of the nozzle <b>114</b> may be adopted in other configuration for formation of the precursor <b>120</b>.

0559With the above-described barrier metal film production apparatus, the barrier metal film <b>123</b> can be formed uniformly to a small thickness. Consequently, the barrier metal film <b>123</b> can be formed highly accurately at a high speed with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example several hundred nanometers wide, which has been provided in the substrate <b>103</b>.

0560Furthermore, the metal member <b>107</b> itself is applied as an electrode for plasma generation. Thus, there is no need for a plasma antenna around the cylindrical portion of the chamber <b>101</b>, and the degree of freedom of the surrounding construction can be increased.

0561A metal film production method and a metal film production apparatus according to the present invention will be described with reference to the accompanying drawings. The metal film production method of the present invention involves a treatment for enhancing adhesion to a barrier metal layer of, for example, tantalum nitride (TaN) formed on the surface of a substrate in order to prevent diffusion into the substrate.

0562According to a first aspect of the present invention, the barrier metal film of TaN is flattened by etching its surface with a diluent gas (e.g., argon: Ar) plasma. Further, the nitrogen atoms in the superficial layer of the barrier metal film are removed using Ar⁺, thereby decreasing the nitrogen content of the superficial layer relative to the interior of the matrix of the barrier metal film (this surface treatment will be referred to hereinafter as denitrification). The denitrification brings a state in which a film of a metal (Ta) is substantially formed in the superficial layer of the single-layer barrier metal film. In this manner, a barrier metal film is produced highly efficiently and reliably in a thin film condition, by use of an inexpensive gas having a high mass number, with the diffusion of the metal being prevented and the adhesion to the metal being maintained.

0563Depending on the material for the barrier metal film, it is possible to perform only the treatment for flattening the surface by etching it with the diluent gas (e.g., argon: Ar) plasma while controlling the power of the plasma and the energization time. By so doing, adhesion can be improved. As the barrier metal film, not only TaN, but tungsten nitride or titanium nitride can be applied. As the diluent gas, not only Ar, but helium, krypton, or neon can be applied.

0564The concrete construction of the apparatus according to the first aspect may be as follows: A source gas containing a halogen (e.g., a chlorine-containing gas) is supplied to the interior of a chamber between a substrate and an etched member made of Ta, and an atmosphere within the chamber is converted into a plasma to generate a chlorine gas plasma. The etched member is etched with the chlorine gas plasma to form a precursor comprising the Ta component contained in the etched member and the chlorine gas. Also, a nitrogen-containing gas is excited, and TaN, a metal nitride, is formed upon reaction between the excited nitrogen and the precursor. The resulting TaN is formed as a film on the substrate kept at a low temperature to form a barrier metal film. This process is performed using a barrier metal film production apparatus. After the barrier metal film is produced in this manner, an Ar gas plasma is generated within the chamber to carry out etching and denitrification.

0565Alternatively, the concrete apparatus construction of the first aspect may be as follows: A chlorine gas is supplied into a chamber, and an atmosphere within the chamber is converted into a plasma to generate a chlorine gas plasma. An etched member made of copper (Cu) is etched with the chlorine gas plasma to form a precursor comprising the Cu component contained in the etched member and chlorine inside the chamber. The temperature of the substrate is rendered lower than the temperature of the etched member to form a film of the Cu component of the precursor on the substrate. This process is performed by use of a metal film production apparatus. Before the substrate having the barrier metal film of TaN formed thereon is housed in the chamber and the Cu component is formed as a film thereon, the Ar gas plasma is generated to carry out etching and denitrification.

0566<figref idref="DRAWINGS">FIG. 28</figref> shows an outline of an apparatus for a film formation process for forming a Cu film. As shown, for example, in <figref idref="DRAWINGS">FIG. 28</figref>, a handling robot <b>401</b> for transporting a substrate is installed at a central site. Around the robot <b>401</b>, there are provided an accommodation device <b>402</b> for accommodating the substrate, a barrier metal CVD <b>403</b> for forming a barrier metal film on the substrate, and a Cu-CVD <b>404</b> for forming a Cu film. The robot <b>401</b> transports the substrate from the accommodation device <b>402</b> to the barrier metal CVD <b>403</b>, from the barrier metal CVD <b>403</b> to the Cu-CVD <b>404</b>, and from the Cu-CVD <b>404</b> to the accommodation device <b>402</b>. With such an apparatus for the film formation process, the metal film production apparatus according to the first aspect is provided in the Cu-CVD <b>404</b>.

0567The metal film production apparatus in the first aspect may be provided in the barrier metal CVD <b>403</b>, or a dedicated metal film production apparatus according to the first aspect may be provided around the robot <b>401</b>.

0568Embodiments of the metal film production method and metal film production apparatus according to the first aspect will be described with reference to the accompanying drawings, with the provision of the apparatus in the Cu-CVD <b>404</b> being taken as an example.

0569<figref idref="DRAWINGS">FIG. 29</figref> is a schematic side view of a metal film production apparatus according to the fifteenth embodiment of the present invention. <figref idref="DRAWINGS">FIG. 30</figref> is a schematic construction drawing showing another example of diluent gas supply means. <figref idref="DRAWINGS">FIG. 31</figref> shows the sectional status of a substrate illustrating a barrier metal film. <figref idref="DRAWINGS">FIGS. 32 and 33</figref> show the concept status of a barrier metal film in denitrification. The illustrated metal film production apparatus corresponds to the Cu-CVD <b>404</b> shown in <figref idref="DRAWINGS">FIG. 1</figref>

0570As shown in <figref idref="DRAWINGS">FIG. 29</figref>, a support platform <b>202</b> is provided near the bottom of a cylindrical chamber <b>201</b> made of, say, a ceramic (an insulating material), and a substrate <b>203</b> is placed on the support platform <b>202</b>. Temperature control means <b>206</b>, as control means, equipped with a heater <b>204</b> and refrigerant flow-through means <b>205</b> is provided in the support platform <b>202</b> so that the support platform <b>202</b> is controlled to a predetermined temperature (for example, a temperature at which the substrate <b>203</b> is maintained at 100 to 200° C.) by the temperature control means <b>206</b>.

0571An upper surface of the chamber <b>201</b> is an opening, which is closed with a copper plate member <b>207</b>, as an etched member, made of a metal. The interior of the chamber <b>201</b> closed with the copper plate member <b>207</b> is maintained at a predetermined pressure by a vacuum device <b>208</b>. A coiled plasma antenna <b>209</b> is provided around a cylindrical portion of the chamber <b>201</b>. A matching instrument <b>210</b> and a power source <b>211</b> are connected to the plasma antenna <b>209</b> to supply power. Plasma generation means is constituted by the plasma antenna <b>209</b>, matching instrument <b>210</b> and power source <b>211</b>.

0572Nozzles <b>212</b> for supplying a source gas (a Cl₂gas diluted with He or Ar to a chlorine concentration of ≦50%, preferably about 10%), containing chlorine as a halogen, to the interior of the chamber <b>201</b> are connected to the cylindrical portion of the chamber <b>201</b> above the support platform <b>202</b>. The nozzle <b>212</b> is fed with the source gas via a flow controller <b>213</b>. Within the chamber <b>201</b>, the source gas is fed toward the copper plate member <b>207</b> (source gas supply means). Fluorine (F), bromine (Br) or iodine (I) can also be applied as the halogen to be incorporated into the source gas.

0573With the above-described metal film production apparatus, the source gas is supplied from the nozzles <b>212</b> into the chamber <b>201</b>, and electromagnetic waves are shot from the plasma antenna <b>209</b> into the chamber <b>201</b>, whereby the Cl₂gas is ionized to generate a Cl₂gas plasma (source gas plasma) <b>214</b>. The pressure inside the chamber <b>201</b>, set by the vacuum device <b>208</b>, is such a high pressure that the plasma density of the Cl₂gas plasma <b>214</b> will be higher toward the wall surface within the chamber <b>201</b>. As means for increasing the plasma density of the Cl₂gas plasma <b>214</b> on the wall surface side, the frequency of the power source <b>211</b> may be increased.

0574The Cl₂gas plasma <b>214</b> causes an etching reaction to the copper plate member <b>207</b>, forming a precursor (Cu_xCl_y) <b>215</b>. At this time, the copper plate member <b>207</b> is maintained by the Cl₂gas plasma <b>214</b> at a predetermined temperature (e.g., 200 to 400° C.) which is higher than the temperature of the substrate <b>203</b>.

0575The precursor (Cu_xCl_y) <b>215</b> formed within the chamber <b>201</b> is transported toward the substrate <b>203</b> controlled to a lower temperature than the temperature of the copper plate member <b>207</b>. The precursor (Cu_xCl_y) <b>215</b> transported toward the substrate <b>203</b> is converted into only Cu ions by a reduction reaction, and directed at the substrate <b>203</b> to form a thin Cu film <b>216</b> on the surface of the substrate <b>203</b>.

0576The reactions involved can be expressed by: <br />2Cu+Cl₂→2CuCl→2Cu↓+Cl₂↑

0577The gases and the etching products that have not been involved in the reaction are exhausted through an exhaust port <b>217</b>.

0578The source gas has been described, with the Cl₂gas diluted with, say, He or Ar taken as an example. However, the Cl₂gas can be used alone, or an HCl gas can also be applied. If the HCl gas is applied, an HCl gas plasma is generated as the source gas plasma. However, the precursor formed by etching of the copper plate member <b>207</b> is Cu_xCl_y. Thus, the source gas may be any gas containing chlorine, and a gas mixture of an HCl gas and a Cl₂gas is also usable. The material for the copper plate member <b>207</b> is not limited to copper (Cu), but it is possible to use a halide forming metal, preferably a chloride forming metal, such as Ag, Au, Pt, Ta, Ti or W. In this case, the resulting precursor is a halide (chloride) of Ag, Au, Pt, Ta, Ti or W, and the thin film formed on the surface of the substrate <b>203</b> is that of Ag, Au, Pt, Ta, Ti or W.

0579Since the metal film production apparatus constructed as above uses the Cl₂gas plasma (source gas plasma) <b>214</b>, the reaction efficiency is markedly increased, and the speed of film formation is fast. Since the Cl₂gas is used as the source gas, moreover, the cost can be markedly decreased. Furthermore, the substrate <b>203</b> is controlled to a lower temperature than the temperature of the copper plate member <b>207</b> by use of the temperature control means <b>206</b>. Thus, the amounts of impurities, such as chlorine, remaining in the thin Cu film <b>216</b> can be decreased, so that a high quality thin Cu film <b>216</b> can be produced.

0580Furthermore, the plasma density of the Cl₂gas plasma <b>214</b> is higher on the wall surface side. Thus, a high density Cl₂gas plasma <b>214</b> can be generated, thus making the film formation speed remarkably high. Even when a large chamber <b>201</b> is used, namely, even for a large substrate <b>203</b>, a thin Cu film <b>216</b> can be formed.

0581Diluent gas nozzles <b>221</b> are provided, as diluent gas supply means, for supplying an Ar gas, as a diluent gas, to the interior of the chamber <b>201</b> above the surface of the substrate <b>203</b>. The Ar gas is supplied from the diluent gas nozzle <b>221</b>, and electromagnetic waves are shot from the plasma antenna <b>209</b> into the chamber <b>201</b>, whereby the Ar gas is ionized to generate an Ar gas plasma (surface treatment plasma generation means). A bias power source <b>220</b> is connected to the support platform <b>202</b>, and a bias voltage is applied thereto for supporting the substrate <b>203</b> on the support platform <b>202</b>.

0582In connection with the diluent gas supply means, when the Ar gas is applied as a diluent gas for the Cl₂gas, a control valve <b>222</b> may be provided at the site of merger between the source gas (Cl₂gas) and the diluent gas (Ar gas), as shown in <figref idref="DRAWINGS">FIG. 30</figref>. By so doing, the Cl₂gas may be stopped during generation of the Ar gas plasma, and only the Ar gas may be supplied through the nozzle <b>212</b>. According to this construction, there is no need for the provision of the diluent gas nozzle <b>221</b>, presenting advantage in space.

0583On the surface of the substrate <b>203</b> carried into the above-described metal film production apparatus, the barrier metal film <b>223</b> of TaN has been formed, as shown in <figref idref="DRAWINGS">FIG. 31</figref>. By generating the Ar gas plasma, the barrier metal film <b>223</b> on the surface of the substrate <b>203</b> is etched with Ar⁺ to flatten the barrier metal film <b>223</b>. Also, denitrification is performed in which the nitrogen atoms (N) of the TaN in the superficial layer of the barrier metal film <b>223</b> are removed to decrease the nitrogen content of the superficial layer relative to the interior of the matrix of the barrier metal film <b>223</b>. As the barrier metal film <b>223</b>, WN or TiN can also be applied.

0584The flattening of the barrier metal film <b>223</b> and its denitrification upon generation of the Ar gas plasma are carried out before formation of the aforementioned thin Cu film <b>216</b>. That is, when the substrate <b>203</b> having the barrier metal film <b>223</b> of TaN formed thereon is received onto the support platform <b>202</b>, the Ar gas is supplied from the diluent gas nozzles <b>221</b> prior to the formation of the thin Cu film <b>216</b>. At the same time, electromagnetic waves are shot from the plasma antenna <b>209</b> into the chamber <b>201</b> to generate an Ar gas plasma.

0585Upon generation of the Ar gas plasma, the surface of the barrier metal film <b>223</b> is etched with Ar⁺ for flattening. As shown in <figref idref="DRAWINGS">FIG. 32</figref>, the barrier metal film <b>223</b> comprises Ta and N in an amorphous state. In this state, N of a lower mass is preferentially removed by Ar⁺, so that the superficial layer of the barrier metal film <b>223</b> (for example, up to a half, preferably about a third, of the entire film thickness) is denitrified. As a result, there emerges the barrier metal film <b>223</b> of a two-layer structure, a metal layer <b>223</b><i>a </i>substantially composed of Ta, and a TaN layer <b>223</b><i>b</i>, as shown in <figref idref="DRAWINGS">FIG. 33</figref>. On this occasion, the entire film thickness of the barrier metal film <b>223</b> remains the film thickness having the single layer.

0586To increase the amount of Ar⁺ generated, control is exercised for increasing the voltage applied to the plasma antenna <b>209</b>, or for increasing the flow rate of the Ar gas. To draw in Ar⁺ toward the substrate <b>203</b>, the bias power source <b>220</b> is controlled to lower the potential of the substrate <b>203</b> to the negative side. For this purpose, schedule control is easy to effect according to a preset schedule. While denitrification is taking place, the depth distribution of the metal layer <b>223</b><i>a </i>is measured. Control over the voltage of the plasma antenna <b>209</b> or the flow rate of the Ar gas, or control of the bias power source <b>220</b> can be exercised based on the results of the measurement

0587After denitrification is performed, the sites of N removed become voids, creating irregularities on the atomic level. Thus, it is preferred to densify the remaining Ta atoms. To make the Ta atoms dense, the present embodiment uses a heater <b>204</b> to heat the substrate <b>203</b> for heat treatment, thereby densifying the Ta atoms (densification means). The heat treatment is performed to such a degree that the atoms do not take a crystal structure (the atoms maintain an amorphous state). The densification means may be plasma heating for heating the substrate <b>203</b>.

0588With the foregoing metal film production apparatus, the Ar gas plasma is generated within the chamber <b>201</b> accommodating the substrate <b>203</b> having the barrier metal film <b>223</b> formed thereon. The Ar gas plasma etches the barrier metal film <b>223</b> to flatten it. The Ar gas plasma also removes the nitrogen atoms to denitrify the barrier metal film <b>223</b>. Thus, there appears the barrier metal film <b>223</b> with a two-layer structure, i.e., the metal layer <b>223</b><i>a </i>composed substantially of Ta and the TaN layer <b>223</b><i>b</i>. Moreover, the entire film thickness can remain the single-layer film thickness. Hence, the barrier metal film <b>223</b> can be in a two-layer structure state without becoming thick, and yet the metal layer <b>223</b><i>a </i>can retain adhesion to the thin Cu film <b>216</b>, while the TaN layer <b>223</b><i>b </i>can prevent diffusion of Cu. Consequently, the thin Cu film <b>216</b> can be formed, with satisfactory adhesion, without diffusion into the substrate <b>203</b>, so that the Cu wiring process can be stabilized.

0589A barrier metal film production method and a barrier metal film production apparatus according to the sixteenth embodiment of the present invention will be described with reference to <figref idref="DRAWINGS">FIGS. 34 to 36</figref>. <figref idref="DRAWINGS">FIG. 34</figref> is a schematic side view of the metal film production apparatus according to the sixteenth embodiment of the present invention. <figref idref="DRAWINGS">FIG. 35</figref> is a view taken along the arrowed line VIII-VIII of <figref idref="DRAWINGS">FIG. 34</figref>. <figref idref="DRAWINGS">FIG. 36</figref> is a view taken along the arrowed line IX-IX of <figref idref="DRAWINGS">FIG. 35</figref>. The same members as the members illustrated in <figref idref="DRAWINGS">FIG. 29</figref> are assigned the same numerals, and duplicate explanations are omitted.

0590An upper surface of the chamber <b>201</b> is an opening, which is closed with a disk-shaped ceiling board <b>230</b> made of an insulating material (for example, a ceramic). An etched member <b>231</b> made of a metal (copper, Cu) is interposed between the opening at the upper surface of the chamber <b>201</b> and the ceiling board <b>230</b>. The etched member <b>231</b> is provided with a ring portion <b>232</b> fitted to the opening at the upper surface of the chamber <b>201</b>. A plurality of (<b>12</b> in the illustrated embodiment) protrusions <b>233</b>, which extend close to the center in the diametrical direction of the chamber <b>201</b> and have the same width, are provided in the circumferential direction on the inner periphery of the ring portion <b>232</b>.

0591The protrusions <b>233</b> are integrally or removably attached to the ring portion <b>232</b>. Notches (spaces) <b>235</b> formed between the protrusions <b>233</b> are present between the ceiling board <b>230</b> and the interior of the chamber <b>201</b>. The ring portion <b>232</b> is earthed, and the plural protrusions <b>233</b> are electrically connected together and maintained at the same potential. Temperature control means (not shown), such as a heater, is provided in the etched member <b>231</b> to control the temperature of the etched member <b>231</b> to 200 to 400° C., for example.

0592Second protrusions shorter in the diametrical direction than the protrusions <b>233</b> can be arranged between the protrusions <b>233</b>. Moreover, short protrusions can be arranged between the protrusion <b>233</b> and the second protrusion. By so doing, the area of copper, an object to be etched, can be secured, with an induced current being suppressed.

0593A planar winding-shaped plasma antenna <b>234</b>, for converting the atmosphere inside the chamber <b>201</b> into a plasma, is provided above the ceiling board <b>230</b>. The plasma antenna <b>234</b> is formed in a planar ring shape parallel to the surface of the ceiling board <b>230</b>. A matching instrument <b>210</b> and a power source <b>211</b> are connected to the plasma antenna <b>234</b> to supply power. The etched member <b>231</b> has the plurality of protrusions <b>233</b> provided in the circumferential direction on the inner periphery of the ring portion <b>232</b>, and includes the notches (spaces) <b>235</b> formed between the protrusions <b>233</b>. Thus, the protrusions <b>233</b> are arranged between the substrate <b>203</b> and the ceiling board <b>230</b> in a discontinuous state relative to the flowing direction of electricity in the plasma antenna <b>234</b>.

0594With the above-described metal film production apparatus, the source gas is supplied through the nozzles <b>212</b> to the interior of the chamber <b>201</b>, and electromagnetic waves are shot from the plasma antenna <b>234</b> into the chamber <b>201</b>. As a result, the Cl₂gas is ionized to generate a Cl₂gas plasma (source gas plasma) <b>214</b>. The etched member <b>231</b>, an electric conductor, is present below the plasma antenna <b>234</b>. However, the Cl₂gas plasma <b>214</b> occurs stably between the etched member <b>231</b> and the substrate <b>203</b>, namely, below the etched member <b>231</b>, under the following action:

0595The action by which the Cl₂gas plasma <b>214</b> is generated below the etched member <b>231</b> will be described. As shown in <figref idref="DRAWINGS">FIG. 36</figref>, a flow A of electricity in the plasma antenna <b>234</b> of the planar ring shape crosses the protrusions <b>233</b>. At this time, an induced current B occurs on the surface of the protrusion <b>233</b> opposed to the plasma antenna <b>234</b>. Since the notches (spaces) <b>235</b> are present in the etched member <b>231</b>, the induced current B flows onto the lower surface of each protrusion <b>233</b>, forming a flow a in the same direction as the flow A of electricity in the plasma antenna <b>234</b> (Faraday shield).

0596When the etched member <b>231</b> is viewed from the substrate <b>203</b>, therefore, there is no flow in a direction in which the flow A of electricity in the plasma antenna <b>234</b> is canceled out. Furthermore, the ring portion <b>232</b> is earthed, and the protrusions <b>233</b> are maintained at the same potential. Thus, even though the etched member <b>231</b>, an electric conductor, exists, the electromagnetic wave is reliably thrown from the plasma antenna <b>234</b> into the chamber <b>201</b>. Consequently, the Cl₂gas plasma <b>214</b> is stably generated below the etched member <b>231</b>.

0597The Cl₂gas plasma <b>214</b> causes an etching reaction to the etched member <b>231</b> made of copper, forming a precursor (Cu_xCl_y) <b>215</b>. At this time, the etched member <b>231</b> is maintained by the Cl₂gas plasma <b>214</b> at a predetermined temperature (e.g., 200 to 400° C.) which is higher than the temperature of the substrate <b>203</b>. The precursor (Cu_xCl_y) <b>215</b> formed within the chamber <b>201</b> is transported toward the substrate <b>203</b> controlled to a lower temperature than the temperature of the etched member <b>231</b>. The precursor (Cu_xCl_y) <b>215</b> transported toward the substrate <b>203</b> is converted into only Cu ions by a reduction reaction, and directed at the substrate <b>203</b> to form a thin Cu film <b>216</b> on the surface of the substrate <b>203</b>.

0598The reactions involved are the same as in the aforementioned fifteenth embodiment. The gases and the etching products, which have not been involved in the reactions, are exhausted through an exhaust port <b>217</b>.

0599Since the metal film production apparatus constructed as above uses the Cl₂gas plasma (source gas plasma) <b>214</b>, the reaction efficiency is markedly increased, and the speed of film formation is fast. Since the Cl₂gas is used as the source gas, moreover, the cost can be markedly decreased. Furthermore, the substrate <b>203</b> is controlled to a lower temperature than the temperature of the etched member <b>231</b> by use of the temperature control means <b>206</b>. Thus, the amounts of impurities, such as chlorine, remaining in the thin Cu film <b>216</b> can be decreased, so that a high quality thin Cu film <b>216</b> can be produced.

0600In addition, the etched member <b>231</b> has the plurality of protrusions <b>233</b> provided in the circumferential direction on the inner periphery of the ring portion <b>232</b>, and includes the notches (spaces) <b>235</b> formed between the protrusions <b>233</b>. Thus, the induced currents generated in the etched member <b>231</b> flow in the same direction as the flowing direction of electricity in the plasma antenna <b>234</b>, when viewed from the substrate <b>203</b>. Therefore, even though the etched member <b>231</b>, an electric conductor, exists below the plasma antenna <b>234</b>, the electromagnetic waves are reliably thrown from the plasma antenna <b>234</b> into the chamber <b>201</b>. Consequently, the Cl₂gas plasma <b>214</b> can be stably generated below the etched member <b>231</b>.

0601Diluent gas nozzles <b>221</b> are provided, as diluent gas supply means, for supplying an Ar gas, as a diluent gas, to the interior of the chamber <b>201</b> above the surface of the substrate <b>203</b>. The Ar gas is supplied from the diluent gas nozzle <b>221</b>, and electromagnetic waves are shot from the plasma antenna <b>234</b> into the chamber <b>201</b>, whereby the Ar gas is ionized to generate an Ar gas plasma (surface treatment plasma generation means). A bias power source <b>220</b> is connected to the support platform <b>202</b>, and a bias voltage is applied thereto for supporting the substrate <b>203</b> on the support platform <b>202</b>.

0602On the surface of the substrate <b>203</b> admitted into the above-described, metal film production apparatus, the barrier metal film <b>223</b> of TaN has been formed, as shown in <figref idref="DRAWINGS">FIG. 31</figref>. By generating the Ar gas plasma, the barrier metal film <b>223</b> on the surface of the substrate <b>203</b> is etched with Ar⁺ to flatten the barrier metal film <b>223</b>. Also, denitrification is performed in which the nitrogen atoms (N) of the TaN in the superficial layer of the barrier metal film <b>223</b> are removed to decrease the nitrogen content of the superficial layer relative to the interior of the matrix of the barrier metal film <b>223</b>. As the barrier metal film <b>223</b>, WN or TiN can also be applied.

0603The flattening of the barrier metal film <b>223</b> and its denitrification upon generation of the Ar gas plasma are carried out before formation of the aforementioned thin Cu film <b>216</b>. The details of the flattening of the barrier metal film <b>223</b>, and the details of the denitrification of this film are the same as in the fifteenth embodiment, and relevant explanations are omitted.

0604With the foregoing metal film production apparatus, as in the fifteenth embodiment, the barrier metal film <b>223</b> can be in a two-layer structure state without becoming thick, and yet the metal layer <b>223</b><i>a </i>can retain adhesion to the thin Cu film <b>216</b>, while the TaN layer <b>223</b><i>b </i>can prevent diffusion of Cu. Consequently, the thin Cu film <b>216</b> can be formed, with satisfactory adhesion, without diffusion into the substrate <b>203</b>, so that the Cu wiring process can be stabilized.

0605A metal film production method and a metal film production apparatus according to the seventeenth embodiment of the present invention will be described with reference to <figref idref="DRAWINGS">FIG. 37</figref>. <figref idref="DRAWINGS">FIG. 37</figref> is a schematic side view of the metal film production apparatus according to the seventeenth embodiment of the present invention. The same members as the members illustrated in <figref idref="DRAWINGS">FIGS. 2 and 7</figref> are assigned the same numerals, and duplicate explanations are omitted.

0606The opening of an upper portion of a chamber <b>201</b> is closed with a ceiling board <b>230</b>, for example, made of a ceramic (an insulating material). An etched member <b>241</b> made of a metal (copper, Cu) is provided on a lower surface of the ceiling board <b>230</b>, and the etched member <b>241</b> is of a quadrangular pyramidal shape. Slit-shaped opening portions <b>242</b> are formed at a plurality of locations (for example, four locations) in the periphery of an upper part of the cylindrical portion of the chamber <b>201</b>, and one end of a tubular passage <b>243</b> is fixed to each of the opening portions <b>242</b>. A tubular excitation chamber <b>244</b> made of an insulator is provided halfway through the passage <b>243</b>, and a coiled plasma antenna <b>245</b> is provided around the excitation chamber <b>244</b>. The plasma antenna <b>245</b> is connected to a matching instrument <b>248</b> and a power source <b>249</b> to receive power. The plasma antenna <b>245</b>, the matching instrument <b>248</b> and the power source <b>249</b> constitute plasma generation means.

0607A flow controller <b>246</b> is connected to the other end of the passage <b>243</b>, and a chlorine-containing source gas (a Cl₂gas diluted with He or Ar to a chlorine concentration of ≦50%, preferably about 10%) is supplied into the passage <b>243</b> via the flow controller <b>246</b>. By shooting electromagnetic waves from the plasma antenna <b>245</b> into the excitation chamber <b>244</b>, the Cl₂gas is ionized to generate a Cl₂gas plasma (source gas plasma) <b>247</b>. Because of the generation of the Cl₂gas plasma <b>247</b>, excited chlorine is fed into the chamber <b>201</b> through the opening portion <b>42</b>, whereupon the etched member <b>241</b> is etched with excited chlorine.

0608With the above-described metal film production apparatus, the source gas is supplied into the passage <b>243</b> via the flow controller <b>246</b> and fed into the excitation chamber <b>244</b>. By shooting electromagnetic waves from the plasma antenna <b>245</b> into the excitation chamber <b>244</b>, the Cl₂gas is ionized to generate a Cl₂gas plasma (source gas plasma) <b>247</b>. Since a predetermined differential pressure has been established between the pressure inside the chamber <b>201</b> and the pressure inside the excitation chamber <b>244</b> by the vacuum device <b>208</b>, the excited chlorine of the Cl₂gas plasma <b>247</b> in the excitation chamber <b>244</b> is fed to the etched member <b>241</b> inside the chamber <b>201</b> through the opening portion <b>242</b>. The excited chlorine causes an etching reaction to the etched member <b>241</b>, forming a precursor (M_xCl_y) <b>215</b> inside the chamber <b>201</b>.

0609At this time, the etched member <b>241</b> is maintained at a predetermined temperature (e.g., 200 to 400° C.), which is higher than the temperature of the substrate <b>203</b>, by a heater <b>250</b>. The precursor (Cu_xCl_y) <b>215</b> formed inside the chamber <b>201</b> is transported toward the substrate <b>203</b> controlled to a lower temperature than the temperature of the etched member <b>241</b>. The precursor (Cu_xCl_y) <b>215</b> transported toward the substrate <b>203</b> is converted into only Cu ions by a reduction reaction, and directed at the substrate <b>203</b> to form a thin Cu film <b>216</b> on the surface of the substrate <b>203</b>.

0610The reactions on this occasion are the same as in the aforementioned fifteenth embodiment, and the gases and etching products that have not been involved in the reactions are exhausted through an exhaust port <b>217</b>.

0611With the above-described metal film production apparatus, the Cl₂gas plasma <b>247</b> is generated in the excitation chamber <b>244</b> isolated from the chamber <b>201</b>. Thus, the substrate <b>203</b> is not exposed to the plasma any more, and the substrate <b>203</b> becomes free from damage from the plasma. As the means for generating the Cl₂gas plasma <b>247</b> in the excitation chamber <b>244</b>, it is possible to use microwaves, laser, electron rays, or synchrotron radiation. It is also permissible to form the precursor by heating a metal filament to a high temperature. The construction for isolating the Cl₂gas plasma <b>247</b> from the substrate <b>203</b> may be the provision of the excitation chamber <b>244</b> in the passage <b>243</b>, or may be other construction, for example, the isolation of the chamber <b>201</b>.

0612The above-described metal film production apparatus is provided with diluent gas nozzles <b>221</b>, as diluent gas supply means, for supplying an Ar gas, as a diluent gas, to the interior of the chamber <b>201</b> above the surface of the substrate <b>203</b>. A coil-shaped surface treatment plasma antenna <b>236</b> is provided on a trunk portion of the chamber <b>201</b>. A matching instrument <b>237</b> and a power source <b>238</b> are connected to the surface treatment plasma antenna <b>236</b> to supply power. The Ar gas is supplied from the diluent gas nozzles <b>221</b>, and electromagnetic waves are shot from the plasma antenna <b>236</b> into the chamber <b>201</b>, whereby the Ar gas is ionized to generate an Ar gas plasma (surface treatment plasma generation means). A bias power source <b>220</b> is connected to the support platform <b>202</b>, and a bias voltage is applied thereto for supporting the substrate <b>203</b> on the support platform <b>202</b>.

0613On the surface of the substrate <b>203</b> admitted into the above-described metal film production apparatus, a barrier metal film <b>223</b> of TaN has been formed, as shown in <figref idref="DRAWINGS">FIG. 31</figref>. By generating the Ar gas plasma, the barrier metal film <b>223</b> on the surface of the substrate <b>203</b> is etched with Ar⁺ to flatten the barrier metal film <b>223</b>. Also, denitrification is performed in which the nitrogen atoms (N) of the TaN in the superficial layer of the barrier metal film <b>223</b> are removed to decrease the nitrogen content of the superficial layer relative to the interior of the matrix of the barrier metal film <b>223</b>. As the barrier metal film <b>223</b>, WN or TiN can also be applied.

0614The flattening of the barrier metal film <b>223</b> and its denitrification upon generation of the Ar gas plasma are carried out before formation of the aforementioned thin Cu film <b>216</b>. The details of the flattening of the barrier metal film <b>223</b> and the denitrification of this film are the same as in the fifteenth embodiment, and relevant explanations are omitted.

0615With the foregoing metal film production apparatus, the barrier metal film <b>223</b> can be in a two-layer structure state without becoming thick, and yet the metal layer <b>223</b><i>a </i>(see <figref idref="DRAWINGS">FIG. 33</figref>) can retain adhesion to the thin Cu film <b>216</b>, while the TaN layer <b>223</b><i>b </i>(see <figref idref="DRAWINGS">FIG. 33</figref>) can prevent diffusion of Cu. Consequently, the thin Cu film <b>216</b> can be formed, with satisfactory adhesion, without diffusion into the substrate <b>203</b>, so that the Cu wiring process can be stabilized.

0616A barrier metal film production method and a barrier metal film production apparatus according to the eighteenth embodiment of the present invention will be described with reference to <figref idref="DRAWINGS">FIG. 38</figref>. <figref idref="DRAWINGS">FIG. 38</figref> is a schematic side view of the metal film production apparatus according to the eighteenth embodiment of the present invention. The same members as the members illustrated in <figref idref="DRAWINGS">FIGS. 29</figref>, <b>34</b> and <b>37</b> are assigned the same numerals, and duplicate explanations are omitted.

0617Compared with the metal film production apparatus of the fifteenth embodiment shown in <figref idref="DRAWINGS">FIG. 29</figref>, the plasma antenna <b>209</b> is not provided around the cylindrical portion of the chamber <b>201</b>, and the matching instrument <b>210</b> and power source <b>211</b> are connected to the copper plate member <b>207</b> for supply of power to the copper plate member <b>207</b>. With the above-described metal film production apparatus, the source gas is supplied from the nozzles <b>212</b> into the chamber <b>201</b>, and electromagnetic waves are shot from the copper plate member <b>207</b> into the chamber <b>201</b>, the Cl₂gas is ionized to generate a Cl₂gas plasma (source gas plasma) <b>214</b>. The Cl₂gas plasma <b>214</b> causes an etching reaction to the copper plate member <b>207</b>, forming a precursor (Cu_xCl_y) <b>215</b>. At this time, the copper plate member <b>207</b> is maintained at a predetermined temperature (e.g., 200 to 400° C.), which is higher than the temperature of the substrate <b>203</b>, by the Cl₂gas plasma <b>214</b>.

0618The precursor (Cu_xCl_y) <b>215</b> formed inside the chamber <b>201</b> is transported toward the substrate <b>203</b> controlled to a lower temperature than the temperature of the copper plate member <b>207</b>. The precursor (Cu_xCl_y) <b>215</b> transported toward the substrate <b>203</b> is converted into only Cu ions by a reduction reaction, and directed at the substrate <b>203</b> to form a thin Cu film <b>216</b> on the surface of the substrate <b>203</b>. The reactions on this occasion are the same as in the aforementioned fifteenth embodiment, and the gases and etching products that have not been involved in the reactions are exhausted through an exhaust port <b>217</b>.

0619With the above-described metal film production apparatus, the copper plate member <b>207</b> itself is applied as an electrode for plasma generation. Thus, the plasma antenna <b>209</b> intended to prepare the thin Cu film <b>216</b> need not be provided around the cylindrical portion of the chamber <b>201</b>.

0620The above-described metal film production apparatus is provided with diluent gas nozzles <b>221</b>, as diluent gas supply means, for supplying an Ar gas, as a diluent gas, to the interior of the chamber <b>201</b> above the surface of the substrate <b>203</b>. Supply of the source gas through the nozzles <b>212</b> is cut off, the Ar gas is supplied from the diluent gas nozzles <b>221</b>, and electromagnetic waves are shot from the copper plate member <b>207</b> into the chamber <b>201</b>. By so doing, the Ar gas is ionized to generate an. Ar gas plasma (surface treatment plasma generation means). A bias power source <b>220</b> is connected to the support platform <b>202</b>, and a bias voltage is applied thereto for supporting the substrate <b>203</b> on the support platform <b>202</b>.

0621On the surface of the substrate <b>203</b> admitted into the above-described metal film production apparatus, a barrier metal film <b>223</b> of TaN has been formed, as shown in <figref idref="DRAWINGS">FIG. 31</figref>. By generating the Ar gas plasma, the barrier metal film <b>223</b> on the surface of the substrate <b>203</b> is etched with Ar⁺ to flatten the barrier metal film <b>223</b>. Also, denitrification is performed in which the nitrogen atoms (N) of the TaN in the superficial layer of the barrier metal film <b>223</b> are removed to decrease the nitrogen content of the superficial layer relative to the interior of the matrix of the barrier metal film <b>223</b>. As the barrier metal film <b>223</b>, WN or TiN can also be applied. As the surface treatment plasma generation means, it is permissible to provide a coiled surface treatment plasma antenna on the trunk portion of the chamber <b>201</b>, and supply power via a matching instrument and a power source, thereby generating an Ar gas plasma.

0622The flattening of the barrier metal film <b>223</b> and its denitrification upon generation of the Ar gas plasma are carried out before formation of the aforementioned thin Cu film <b>216</b>. The details of the flattening of the barrier metal film <b>223</b> and the denitrification of this film are the same as in the fifteenth embodiment, and relevant explanations are omitted.

0623With the foregoing metal film production apparatus, as in the fifteenth embodiment, the barrier metal film <b>223</b> can be in a two-layer structure state without becoming thick, and the metal layer <b>223</b><i>a </i>(see <figref idref="DRAWINGS">FIG. 33</figref>) can retain adhesion to the thin Cu film <b>216</b>, while the TaN layer <b>223</b><i>b </i>(see <figref idref="DRAWINGS">FIG. 33</figref>) can prevent diffusion of Cu. Consequently, the thin Cu film <b>216</b> can be formed, with satisfactory adhesion, without diffusion into the substrate <b>203</b>, so that the Cu wiring process can be stabilized.

0624Next, an example in which embodiments of the metal film production method and metal film production apparatus according to the first aspect are provided in the barrier metal CVD <b>403</b> will be described with reference to <figref idref="DRAWINGS">FIG. 39</figref>. <figref idref="DRAWINGS">FIG. 39</figref> schematically shows a side view of the metal film production apparatus according to the nineteenth embodiment of the present invention.

0625As shown in the drawing, a support platform <b>252</b> is provided near the bottom of a cylindrical chamber <b>251</b> made of, say, a ceramic (an insulating material), and a substrate <b>253</b> is placed on the support platform <b>252</b>. Temperature control means <b>256</b> equipped with a heater <b>254</b> and refrigerant flow-through means <b>255</b> is provided in the support platform <b>252</b> so that the support platform <b>252</b> is controlled to a predetermined temperature (for example, a temperature at which the substrate <b>253</b> is maintained at 100 to 200° C.) by the temperature control means <b>256</b>.

0626An upper surface of the chamber <b>251</b> is an opening, which is closed with a metal member <b>257</b>, as an etched member, made of a metal (e.g., W, Ti, Ta, or TiSi). The interior of the chamber <b>251</b> closed with the metal member <b>257</b> is maintained at a predetermined pressure by a vacuum device <b>258</b>. A plasma antenna <b>259</b>, as a coiled winding antenna of plasma generation means, is provided around a cylindrical portion of the chamber <b>251</b>. A matching instrument <b>260</b> and a power source <b>261</b> are connected to the plasma antenna <b>259</b> to supply power.

0627Nozzles <b>262</b> for supplying a source gas (a Cl₂gas diluted with He or Ar to a chlorine concentration of ≦50%, preferably about 10%), containing chlorine as a halogen, to the interior of the chamber <b>251</b> are connected to the cylindrical portion of the chamber <b>251</b> below the metal member <b>257</b>. The nozzle <b>262</b> is open toward the horizontal, and is fed with the source gas via a flow controller <b>263</b> (halogen gas supply means). Fluorine (F), bromine (Br) or iodine (I) can also be applied as the halogen to be incorporated into the source gas.

0628Slit-shaped opening portions <b>264</b> are formed at a plurality of locations (for example, four locations) in the periphery of a lower part of the cylindrical portion of the chamber <b>251</b>, and one end of a tubular passage <b>265</b> is fixed to each of the opening portions <b>264</b>. A tubular excitation chamber <b>266</b> made of an insulator is provided halfway through the passage <b>265</b>, and a coiled plasma antenna <b>267</b> is provided around the excitation chamber <b>266</b>. The plasma antenna <b>267</b> is connected to a matching instrument <b>268</b> and a power source <b>269</b> to receive power. The plasma antenna <b>267</b>, the matching instrument <b>268</b> and the power source <b>269</b> constitute excitation means. A flow controller <b>270</b> is connected to the other end of the passage <b>265</b>, and an ammonia gas (NH₃gas) as a nitrogen-containing gas is supplied into the passage <b>265</b> via the flow controller <b>270</b>.

0629With the above-described metal film production apparatus, the source gas is supplied through the nozzles <b>262</b> to the interior of the chamber <b>251</b>, and electromagnetic waves are shot from the plasma antenna <b>259</b> into the chamber <b>251</b>. As a result, the Cl₂gas is ionized to generate a Cl₂gas plasma (source gas plasma) <b>271</b>. The Cl₂gas plasma <b>271</b> causes an etching reaction to the metal member <b>257</b>, forming a precursor (M_xCl_y: M is a metal such as W, Ti, Ta or TiSi) <b>272</b>.

0630Separately, the NH₃gas is supplied into the passage <b>265</b> via the flow controller <b>270</b> and fed into the excitation chamber <b>266</b>. By shooting electromagnetic waves from the plasma antenna <b>267</b> into the excitation chamber <b>266</b>, the NH₃gas is ionized to generate an NH₃gas plasma <b>263</b>. Since a predetermined differential pressure has been established between the pressure inside the chamber <b>251</b> and the pressure inside the excitation chamber <b>266</b> by the vacuum device <b>258</b>, the excited ammonia of the NH₃gas plasma <b>273</b> in the excitation chamber <b>266</b> is fed to the precursor (M_xCl_y) <b>272</b> inside the chamber <b>251</b> through the opening portion <b>264</b>.

0631That is, excitation means for exciting the nitrogen-containing gas in the excitation chamber <b>266</b> isolated from the chamber <b>251</b> is constructed. Because of this construction, the metal component of the precursor (M_xCl_y) <b>272</b> and ammonia react to form a metal nitride (MN) (formation means). At this time, the metal member <b>257</b> and the excitation chamber <b>266</b> are maintained by the plasmas at predetermined temperatures (e.g., 200 to 400° C.) which are higher than the temperature of the substrate <b>253</b>.

0632The metal nitride (MN) formed within the chamber <b>251</b> is transported toward the substrate <b>253</b> controlled to a low temperature, whereby a thin MN film <b>274</b> (a TaN film if the metal member <b>257</b> of Ta is applied) is formed on the surface of the substrate <b>253</b>.

0633The reaction for formation of the thin MN film <b>274</b> can be expressed by: <br />2MCl+2NH₃→2MN↓+HCl↑+2H₂↑

0634The gases and the etching products that have not been involved in the reactions are exhausted through an exhaust port <b>277</b>.

0635The source gas has been described, with the Cl₂gas diluted with, say, He or Ar taken as an example. However, the Cl₂gas can be used alone, or an HCl gas can also be applied. When the HCl gas is applied, an HCl gas plasma is generated as the source gas plasma. Thus, the source gas may be any gas containing chlorine, and a gas mixture of an HCl gas and a Cl₂gas is also usable. As the material for the metal member <b>257</b>, it is possible to use an industrially applicable metal such as Ag, Au, Pt or Si. Further, the NH₃gas is supplied into the passage <b>265</b> and fed into the excitation chamber <b>266</b>. At the same time, electromagnetic waves are shot from the plasma antenna <b>267</b> into the excitation chamber <b>266</b> to generate the NH₃gas plasma <b>263</b>. However, an NH₃gas plasma can be generated within the chamber <b>251</b> by supplying an NH₃gas into the chamber <b>251</b> and supplying power to the plasma antenna <b>259</b>. In this case, the chamber <b>265</b>, excitation chamber <b>266</b>, plasma antenna <b>267</b>, matching instrument <b>268</b> and power source <b>269</b> can be omitted.

0636With the above-described metal film production apparatus, the metal is formed by plasmas to produce the thin MN film <b>274</b> as the barrier metal film. Thus, the barrier metal film can be formed uniformly to a small thickness. Consequently, the barrier metal film can be formed highly accurately at a high speed with excellent burial properties in a very small thickness even to the interior of a tiny depression, for example, several hundred nanometers wide, which has been provided in the substrate <b>253</b>.

0637The above-described metal film production apparatus is provided with diluent gas nozzles <b>276</b>, as diluent gas supply means, for supplying an Ar gas, as a diluent gas, to the interior of the chamber <b>251</b> above the surface of the substrate <b>253</b>. The Ar gas is supplied from the diluent gas nozzles <b>276</b>, and electromagnetic waves are shot from the plasma antenna <b>259</b> into the chamber <b>251</b>, whereby the Ar gas is ionized to generate an Ar gas plasma (surface treatment plasma generation means). A bias power source <b>277</b> is connected to the support platform <b>252</b>, and a bias voltage is applied thereto for supporting the substrate <b>253</b> on the support platform <b>252</b>.

0638With the above-described metal film production apparatus, the thin MN film <b>274</b> as a barrier metal film is formed, whereafter an Ar gas plasma is generated. By generating the Ar gas plasma, the barrier metal film on the surface of the substrate <b>253</b> is etched with Ar⁺ to flatten the barrier metal film. Also, denitrification is performed in which the nitrogen atoms (N) of the TaN in the superficial layer of the barrier metal film are removed. After flattening of the barrier metal film and the removal of the nitrogen atoms (N) of the TaN in the superficial layer for denitrification, a thin copper (Cu) film or a thin aluminum (Al) film is formed on the barrier metal film by a film forming device. The details of the flattening of the barrier metal film and the denitrification of this film upon generation of the Ar gas plasma are the same as in the fifteenth embodiment. Thus, relevant explanations are omitted.

0639With the foregoing metal film production apparatus, as in the fifteenth embodiment, the barrier metal film can be in a two-layer structure state without becoming thick, and the resulting metal layer can retain adhesion to a thin metal film formed by film formation in the subsequent step. Whereas the TaN layer can prevent diffusion of metal during film formation in the subsequent step. Consequently, the thin metal film (thin Cu film) during film formation in the subsequent step can be formed, with satisfactory adhesion, without diffusion into the substrate <b>253</b>, so that the Cu wiring process can be stabilized.

0640The construction of the metal film production apparatus for producing the barrier metal film may employ a device of the type generating a capacitive coupling plasma, or a device of the remote type which generates a plasma in a manner isolated from a film formation chamber.

0641Next, the second aspect of the present invention will be described. According to the second aspect, the barrier metal film of TaN is subjected to a surface treatment in which this film is reacted in a reducing gas (e.g. hydrogen gas) atmosphere (a hydrogen gas plasma) to remove the nitrogen atoms in the superficial layer of the barrier metal film, thereby decreasing the nitrogen content of the superficial layer relative to the interior of the matrix of the barrier metal film (this treatment will be referred to hereinafter as denitrification). The denitrification brings a state in which a film of the metal (Ta) is substantially formed in the superficial layer of the single-layer barrier metal film. In this manner, a barrier metal film is produced highly efficiently and reliably in a thin film condition, with the diffusion of the metal being prevented and the adhesion to the metal being maintained.

0642As the reducing gas, a nitrogen gas as well as the hydrogen gas can be applied, or a carbon monoxide gas can also be applied. If the carbon monoxide gas is used, denitrification can be carried out in a carbon monoxide gas atmosphere, without generation of plasma.

0643The concrete construction of the apparatus according to the second aspect of the invention may be as follows: A source gas containing a halogen (e.g., a chlorine-containing gas) is supplied to the interior of a chamber between a substrate and an etched member of Ta, and an atmosphere within the chamber is converted into a plasma to generate a chlorine gas plasma. The etched member is etched with the chlorine gas plasma to form a precursor comprising the Ta component contained in the etched member and the chlorine gas. Also, a nitrogen-containing gas is excited, and TaN, a metal nitride, is formed upon reaction between the excited nitrogen and the precursor. The resulting TaN is formed as a film on the substrate kept at a low temperature to form a barrier metal film. This process is performed using a barrier metal film production apparatus. After the barrier metal film is produced in this manner, a hydrogen gas plasma (or a nitrogen gas plasma) is generated within the chamber to react radical hydrogen with nitrogen, performing denitrification. That is, the barrier metal film production apparatus shown in <figref idref="DRAWINGS">FIG. 39</figref> can be applied.

0644Alternatively, the concrete construction of the apparatus of the second aspect may be as follows: A chlorine gas is supplied into the chamber, and an atmosphere within the chamber is converted into a plasma to generate a chlorine gas plasma. An etched member made of copper (Cu) is etched with the chlorine gas plasma to form a precursor comprising the Cu component contained in the etched member and chlorine inside the chamber. The temperature of the substrate is rendered lower than the temperature of the etched member to form a film of the Cu component of the precursor on the substrate. This process is performed using a metal film forming device. Before the substrate having a barrier metal film of TaN formed thereon is housed in the chamber and the Cu component is formed as a film thereon, a hydrogen gas plasma (or a nitrogen gas plasma) is generated within the chamber to react radical hydrogen with nitrogen, performing denitrification. That is, the metal film production apparatus shown, for example, in FIGS. <b>29</b>, <b>34</b>, <b>37</b> and <b>38</b> can be applied.

0645Embodiments of the metal film production method and metal film production apparatus according to the second aspect will be described, with the provision of the apparatus in the Cu-CVD <b>404</b> (see <figref idref="DRAWINGS">FIG. 28</figref>) being taken as an example.

0646<figref idref="DRAWINGS">FIG. 40</figref> shows the conceptual construction of a metal film production apparatus according to the twentieth embodiment of the present invention. <figref idref="DRAWINGS">FIG. 41</figref> shows the concept status of the barrier metal film in denitrification. The illustrated metal film production apparatus has the conceptual construction of the metal film production apparatus according to the fifteenth embodiment shown in <figref idref="DRAWINGS">FIG. 29</figref>, in which the gas supplied through the nozzle <b>21</b> is different. Thus, the formation of the thin Cu film in the metal film production apparatus is the same, and its explanation is omitted hereinbelow.

0647As shown in <figref idref="DRAWINGS">FIG. 40</figref>, reducing gas nozzles <b>225</b> are provided, as reducing gas supply means, for supplying a hydrogen gas (H₂gas) as a reducing gas, to the interior of a chamber <b>201</b> above the surface of a substrate <b>203</b>. The H₂gas is supplied from the reducing gas nozzles <b>225</b>, and electromagnetic waves are shot from a plasma antenna <b>209</b> into the chamber <b>201</b>, whereby the H₂gas is ionized to generate an H₂gas plasma (surface treatment means). On the surface of the substrate <b>203</b> admitted into the illustrated metal film production apparatus, a barrier metal film <b>223</b> of TaN (see <figref idref="DRAWINGS">FIG. 31</figref>) has been formed. Upon generation of the H₂gas plasma, hydrogen radicals H* react with the nitrogen atoms (N) of the TaN in the superficial layer of the substrate <b>203</b>, forming ammonia NH₃, which is exhausted. Thus, the nitrogen atoms (N) in the superficial layer are removed to decrease the nitrogen content of the superficial layer relative to the interior of the matrix of the barrier metal film <b>223</b> (denitrification).

0648The denitrification of the barrier metal film <b>223</b> (see <figref idref="DRAWINGS">FIG. 31</figref>) caused by generation of the H₂gas plasma is performed before formation of the thin Cu film <b>216</b> explained in the fifteenth embodiment of <figref idref="DRAWINGS">FIG. 29</figref>. That is, when the substrate <b>203</b> having the barrier metal film <b>223</b> of TaN (see <figref idref="DRAWINGS">FIG. 31</figref>) formed thereon is admitted onto a support platform <b>202</b>, the H₂gas is supplied from the reducing gas nozzles <b>225</b> prior to the formation of the thin Cu film <b>216</b> (see <figref idref="DRAWINGS">FIG. 29</figref>). At the same time, electromagnetic waves are shot from the plasma antenna <b>209</b> into the chamber <b>201</b>, whereby the H₂gas plasma is generated.

0649Upon generation of the H₂gas plasma, hydrogen radicals H* react with the nitrogen atoms (N) of the TaN in the superficial layer of the substrate <b>203</b>, forming ammonia NH₃, which is exhausted. The hydrogen radicals H* do not affect the metal, but react with only the nitrogen atoms (N), thereby forming ammonia NH₃.

0650That is, the reaction <br />N+3H*→NH₃<br /> forms ammonia NH₃, which is exhausted.

0651As shown in <figref idref="DRAWINGS">FIG. 41</figref>, the barrier metal film <b>223</b> comprises Ta and N in an amorphous state. In this state, hydrogen radicals H* react with N, forming ammonia NH₃, which is exhausted. In this manner, the superficial layer of the barrier metal film <b>223</b> (for example, up to a half, preferably about a third, of the entire film thickness) is denitrified. As a result, there emerges the barrier metal film <b>223</b> of a two-layer structure, a metal layer <b>223</b><i>a </i>substantially composed of Ta, and a TaN layer <b>223</b><i>b</i>, as shown in <figref idref="DRAWINGS">FIG. 33</figref>. On this occasion, the entire film thickness of the barrier metal film <b>223</b> remains the film thickness constructed by the single layer.

0652Hydrogen radicals H* have a short life and penetrate narrow sites. Thus, the pressure inside the chamber <b>201</b> is lowered to decrease the density, or the temperature of the substrate <b>203</b> is controlled, thereby making it possible to increase hydrogen radicals H* (prevent them from colliding with each other), or to control the depth of the metal layer <b>223</b><i>a </i>composed substantially of Ta (see <figref idref="DRAWINGS">FIG. 33</figref>). Setting of the pressure can be performed by increasing the mean free path (MFP) which is the value of the distance traveled by a hydrogen radical H* before collision. Normally, the distance from the center of the plasma to the substrate <b>203</b> depends on the apparatus. To increase the mean free path, control is exercised, with the pressure inside the chamber <b>201</b> being lowered. If the apparatus has the support platform <b>202</b> movable upward and downward, the support platform <b>202</b> is raised, without a fall in the pressure, to bring the substrate <b>203</b> close to the center of the plasma, whereby the mean free path can be increased relatively.

0653With the foregoing metal film production apparatus, the hydrogen gas plasma is generated within the chamber <b>201</b> accommodating the substrate <b>203</b> having the barrier metal film <b>223</b> formed thereon. The hydrogen radicals H* take part in denitrification in which they react with the nitrogen atoms (N), forming ammonia NH₃, which is exhausted. Thus, there can appear the barrier metal film <b>223</b> with a two-layer structure, i.e., the metal layer <b>223</b><i>a </i>composed substantially of Ta (see <figref idref="DRAWINGS">FIG. 33</figref>) and the TaN layer <b>223</b><i>b </i>(see <figref idref="DRAWINGS">FIG. 33</figref>). Moreover, the entire film thickness can remain the single-layer film thickness. Hence, the barrier metal film <b>223</b> can be in a two-layer structure state without becoming thick, and yet the metal layer <b>223</b><i>a </i>(see <figref idref="DRAWINGS">FIG. 33</figref>) can retain adhesion to the thin Cu film <b>216</b> (see <figref idref="DRAWINGS">FIG. 29</figref>), while the TaN layer <b>223</b><i>b </i>(see <figref idref="DRAWINGS">FIG. 33</figref>) can prevent diffusion of Cu. Consequently, the thin Cu film <b>216</b> (see <figref idref="DRAWINGS">FIG. 29</figref>) can be formed, with satisfactory adhesion, without diffusion into the substrate <b>203</b>, so that the Cu wiring process can be stabilized. In addition, denitrification can be carried out with high efficiency.

0654The hydrogen gas has been taken as an example of the reducing gas for the purpose of explanation. In the case of the metal film production apparatus in which a hydrogen atmosphere is not usable, a nitrogen gas can be used as the reducing gas. In this case, a nitrogen gas plasma is generated, whereupon N* reacts with the nitrogen atoms (N) of the barrier metal film <b>223</b>. As a result, N+N*→N₂, which is exhausted. The use of the nitrogen gas enables denitrification to take place easily, even if a limitation is imposed on the use of the reducing gas.

0655Alternatively, a carbon monoxide gas can be used as the reducing gas. In this case, no plasma is generated, and in the unchanged atmosphere, CO reacts with the nitrogen atoms (N) of the barrier metal film <b>223</b>, as in 2N+2CO→2CN+O₂, which are exhausted. The use of the carbon monoxide gas enables denitrification to take place, simply by temperature control of the substrate <b>203</b> without generation of a plasma. Thus, consumption of power can be decreased.

0656The twentieth embodiment described above can be applied to the metal film production apparatuses of the sixteenth to eighteenth embodiments shown in <figref idref="DRAWINGS">FIGS. 34</figref>, <b>37</b> and <b>38</b>. It is also applicable to the barrier metal film production apparatus of the nineteenth embodiment shown in <figref idref="DRAWINGS">FIG. 39</figref>. It is also possible to combine the flattening of the surface with Ar⁺ upon generation of the Ar gas plasma in the fifteenth to nineteenth embodiments with denitrification using the reducing gas plasma. In this case, an Ar gas and a reducing gas may be mixed and supplied into the chamber <b>1</b>, or an Ar gas and a reducing gas may be supplied sequentially.

0657Next, the third aspect of the present invention will be described. According to the third aspect, a barrier metal film of TaN is subjected to a treatment for etching the surface and forming nuclei of silicon atoms by use of a plasma of a silicon-containing gas (for example, silane, SiH₄, a hydride of silicon). Silicon, which is not a foreign matter, has good adhesion to a metal, and the formation of nuclei of silicon atoms on the surface can increase adhesion between the metal of a barrier metal film and a metal to be formed as a film thereon. By this method, a barrier metal film preventing diffusion of a metal and retaining adhesion to the metal is produced with good efficiency and without deterioration of performance.

0658As the silicon-containing gas, a disilane (Si₂H₄) gas or a trisilane (Si₂H₈) can be used in addition to the SiH₄gas. If hydrogen cannot be used, an SiCl₄gas, an SiH₂Cl₂gas or an SiHCl₃gas can be applied. Any such gas may be diluted with a diluent gas and supplied. By controlling the dilution ratio or the flow rate of the gas, or controlling the power of its plasma, it becomes possible to control the depth of etching on the surface or the sizes of the nuclei of silicon atoms.

0659A concrete apparatus construction according to the third aspect of the invention may be as follows: Using a barrier metal film production apparatus, a source gas containing a halogen (e.g., a chlorine-containing gas) is supplied to the interior of a chamber between a substrate and an etched member of Ta, and an atmosphere within the chamber is converted into a plasma to generate a chlorine gas plasma. The etched member is etched with the chlorine gas plasma to form a precursor comprising the Ta component contained in the etched member and the chlorine gas. Also a nitrogen-containing gas is excited, and TaN, a metal nitride, is formed upon reaction between the excited nitrogen and the precursor. The resulting TaN is formed as a film on the substrate kept at a low temperature to form a barrier metal film. After the barrier metal film is produced in this manner, an SiH₄gas plasma, a gas containing silicon, is generated within the chamber to form crystal grains of Si. That is, a barrier metal film production apparatus shown, for example, in <figref idref="DRAWINGS">FIG. 39</figref> can be applied.

0660Alternatively, a concrete apparatus construction according to the third aspect of the invention may be as follows: A chlorine gas is supplied into the chamber, and an atmosphere within the chamber is converted into a plasma to generate a chlorine gas plasma. An etched member made of copper (Cu) is etched with the chlorine gas plasma to form a precursor comprising the Cu component contained in the etched member and chlorine inside the chamber. The temperature of the substrate is rendered lower than the temperature of the etched member to form a film of the Cu component of the precursor on the substrate. This process is performed using a metal film forming device. The substrate having a barrier metal film of TaN formed thereon is housed in the chamber. Before the Cu component is formed as a film thereon, an SiH₄gas plasma, a plasma of a silicon-containing gas, is generated within the chamber to form crystal grains of Si. That is, the metal film production apparatus shown, for example, in <figref idref="DRAWINGS">FIG. 29</figref>, <b>34</b>, <b>37</b> or <b>38</b> can be applied.

0661An embodiment of the metal film production method and metal film production apparatus according to the third aspect will be described, with the provision of the apparatus in the Cu-CVD <b>404</b> (see <figref idref="DRAWINGS">FIG. 28</figref>) being taken as an example.

0662<figref idref="DRAWINGS">FIG. 42</figref> shows the conceptual construction of a metal film production apparatus according to the twenty-first embodiment of the present invention. <figref idref="DRAWINGS">FIG. 43</figref> shows the concept status of a barrier metal film in the formation of nuclei of Si. The illustrated metal film production apparatus has the conceptual construction of the metal film production apparatus according to the fifteenth embodiment shown in <figref idref="DRAWINGS">FIG. 29</figref>, in which the gas supplied through the nozzles <b>21</b> is made different. Thus, the formation of the thin Cu film in the metal film production apparatus is the same, and its explanation is omitted hereinbelow.

0663As shown in <figref idref="DRAWINGS">FIG. 42</figref>, silicon-containing gas nozzles <b>228</b> are provided, as silicon-containing gas supply means, for supplying a silane gas (SiH₄gas), as a gas containing silicon, to the interior of a chamber <b>201</b> above the surface of a substrate <b>203</b>. An SiH₄gas diluted with hydrogen is supplied through the silicon-containing gas nozzles <b>228</b>, and electromagnetic waves are shot from a plasma antenna <b>209</b> into the chamber <b>201</b>, whereby the hydrogen-diluted SiH₄gas is ionized to generate an SiH₄gas plasma (surface treatment plasma means). On the surface of the substrate <b>203</b> admitted into the illustrated metal film production apparatus, a barrier metal film <b>223</b> of TaN (see <figref idref="DRAWINGS">FIG. 31</figref>) has been formed. Generation of the SiH₄gas plasma results in the growth of crystal grains of Si and the appearance of H₂. While film formation is proceeding, crystal grains of Si are formed as nuclei on the superficial layer of the substrate <b>203</b> by the etching action of H₂.

0664The formation of the nuclei of Si upon generation of the SiH₄gas plasma is performed before formation of the thin Cu film <b>216</b> explained in the fifteenth embodiment of <figref idref="DRAWINGS">FIG. 29</figref>. That is, when the substrate <b>203</b> having the barrier metal film <b>223</b> of TaN (see <figref idref="DRAWINGS">FIG. 31</figref>) formed there on is admitted onto the support platform <b>202</b>, a hydrogen-diluted SiH₄gas is supplied through the silicon-containing gas nozzles <b>228</b> prior to the formation of the thin Cu film <b>216</b> (see <figref idref="DRAWINGS">FIG. 29</figref>). Also, electromagnetic waves are shot from the plasma antenna <b>209</b> into the chamber <b>201</b> to generate an SiH₄gas plasma. The ratio of SiH₄to hydrogen in the hydrogen-diluted SiH₄gas is set, for example, as follows: SiH₄/hydrogen≦5/100. As the diluent gas, argon, helium, neon or other diluent gas can be applied in addition to hydrogen.

0665When the SiH₄gas plasma is generated, the reaction <br />SiH₄→Si+H₂<br /> proceeds. As a result, while film formation is proceeding, crystal grains of Si are formed as nuclei on the superficial layer of the barrier metal film <b>223</b> by the etching action of H₂, as shown in <figref idref="DRAWINGS">FIG. 43</figref>. The sizes of the nuclei of Si can be controlled appropriately by controlling the conditions for the plasma, the ratio of hydrogen dilution, the flow rate of the gas, etc. The etching action of H₂removes the nitrogen atoms (N) of the barrier metal film <b>223</b>, and can bring the state of the barrier metal film <b>223</b> having a two-layer structure, a metal layer <b>223</b><i>a </i>substantially composed of Ta (see <figref idref="DRAWINGS">FIG. 33</figref>), and a TaN layer <b>223</b><i>b </i>(see <figref idref="DRAWINGS">FIG. 33</figref>).

0666Since the SiH₄gas is diluted with hydrogen, the crystallinity of Si can be improved, and its nuclei are easy to form. Silicon, which is not a foreign matter, has good adhesion to Ta and Cu, and the formation of nuclei of Si on the surface of the barrier metal film <b>223</b> can increase adhesion between Ta of the barrier metal film <b>223</b> and Cu to be formed as a film thereon. By this method, a barrier metal film <b>223</b> preventing diffusion of the metal and retaining adhesion to the metal is produced with good efficiency and without deterioration of performance.

0667With the above-described metal film production apparatus, the SiH₄gas plasma is generated within the chamber <b>201</b> accommodating the substrate <b>203</b> having the barrier metal film <b>223</b> formed thereon, whereby crystal grains of Si are formed as nuclei on the superficial layer of the barrier metal film <b>223</b>. Thus, adhesion to Ta and Cu can be improved. Consequently, the barrier metal film <b>223</b> can be formed with satisfactory adhesion and anti-diffusion properties without becoming thick, so that the Cu wiring process can be stabilized.

0668The twenty-first embodiment described above can be applied to the metal film production apparatuses of the sixteenth to eighteenth embodiments shown in <figref idref="DRAWINGS">FIGS. 34</figref>, <b>37</b> and <b>38</b>. It is also applicable to the barrier metal film production apparatus of the nineteenth embodiment shown in <figref idref="DRAWINGS">FIG. 39</figref>. It is also possible to combine the flattening of the surface with Ar⁺ upon generation of the Ar gas plasma in the fifteenth to nineteenth embodiments with the formation of crystal grains of Si as nuclei on the superficial layer of the barrier metal film <b>223</b>. In this case, a common nozzle can be used by diluting an SiH₄gas with an Ar gas, and the flattening of the surface and the formation of Si nuclei can be easily switched by controlling the flow rate of the Ar gas.

0669While the present invention has been described by the foregoing embodiments, it is to be understood that the invention is not limited thereby, but may be varied in many other ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the appended claims.